U.S. patent application number 17/632253 was filed with the patent office on 2022-09-08 for composition and article including fluoropolymer and branched silsesquioxane polymer.
The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Chetan P. Jariwala, Michael H. Mitchell, Tho Q. Nguyen, Jitendra S. Rathore.
Application Number | 20220282079 17/632253 |
Document ID | / |
Family ID | 1000006409338 |
Filed Date | 2022-09-08 |
United States Patent
Application |
20220282079 |
Kind Code |
A1 |
Mitchell; Michael H. ; et
al. |
September 8, 2022 |
Composition and Article Including Fluoropolymer and Branched
Silsesquioxane Polymer
Abstract
The composition can include a fluoropolymer and a branched
silsesquioxane polymer having terminal --Si(R.sup.3).sub.3 groups
and units having formula, in which * represents a bond to another
silicon atom in the branched silsesquioxane polymer, R is an
organic group comprising an aliphatic carbon-carbon double bond,
and R.sup.3 is a non-hydrolyzable group or hydrogen. The
fluoropolymer can be crosslinked with the branched silsesquioxane
polymer. An article can include a first composition including a
fluoropolymer in contact with a second composition including a
silicone, wherein at least one of the first composition or second
composition includes the branched silsesquioxane polymer. At least
one of the fluoropolymer or the silicone can be crosslinked with a
branched silsesquioxane polymer including terminal
--Si(R.sup.3).sub.3 groups and units having formula, in which R* is
an organic group comprising a carbon-carbon bond between the
branched silsesquioxane polymer and the fluoropolymer, the
silicone, or another R* group.
Inventors: |
Mitchell; Michael H.;
(Edina, MN) ; Jariwala; Chetan P.; (Woodbury,
MN) ; Rathore; Jitendra S.; (Woodbury, MN) ;
Nguyen; Tho Q.; (Bloomington, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Family ID: |
1000006409338 |
Appl. No.: |
17/632253 |
Filed: |
September 3, 2020 |
PCT Filed: |
September 3, 2020 |
PCT NO: |
PCT/US2020/049273 |
371 Date: |
February 2, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62896069 |
Sep 5, 2019 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 2312/00 20130101;
C08L 27/18 20130101; C08L 27/16 20130101; C08L 29/10 20130101; C08L
27/20 20130101; C08L 27/24 20130101 |
International
Class: |
C08L 27/24 20060101
C08L027/24; C08L 27/18 20060101 C08L027/18; C08L 27/20 20060101
C08L027/20; C08L 27/16 20060101 C08L027/16; C08L 29/10 20060101
C08L029/10 |
Claims
1. A composition comprising: a fluoropolymer; and a branched
silsesquioxane polymer comprising terminal --Si(R.sup.3).sub.3
groups and units represented by formula: ##STR00016## wherein *
represents a bond to another silicon atom in the branched
silsesquioxane polymer; each R is independently an organic group
comprising an aliphatic carbon-carbon double bond; and each R.sup.3
is independently a non-hydrolyzable group with the proviso that one
R.sup.3 may be hydrogen.
2. The composition of claim 1, wherein the branched silsesquioxane
polymer further comprises units represented by formula:
##STR00017## wherein. * represents a bond to another silicon atom
in the branched silsesquioxane polymer; and each R.sup.2 is
independently hydrogen, alkyl, aryl, or alkylene at least one of
interrupted or terminated by arylene or heterocyclylene, wherein
alkyl and alkylene at least one of interrupted or terminated by
arylene or heterocyclylene are unsubstituted or substituted with
halogen and optionally interrupted by at least one catenated --O--,
and wherein aryl, arylene, and heterocyclylene are unsubstituted or
substituted by at least one alkyl, alkoxy, halogen, or combination
thereof.
3. The composition of claim 1, wherein each R is independently
represented by --Y--Z, wherein Y is a bond, alkylene, arylene, or
alkylene at least one of interrupted or terminated by arylene, and
wherein Z is --CH.dbd.CH.sub.2, --O--CH.dbd.CH.sub.2,
--O--C(O)--CH.dbd.CH.sub.2, --O--C(O)--C(CH.sub.3).dbd.CH.sub.2,
--NR'--C(O)--CH.dbd.CH.sub.2, or
--NR'--C(O)--C(CH.sub.3).dbd.CH.sub.2, wherein R' is hydrogen or
alkyl having up to four carbon atoms, or wherein --Y--Z is
--CH.sub.2--CH.dbd.CH.sub.2.
4. The composition of claim 1, wherein each R.sup.3 is
independently alkyl having up to four carbon atoms.
5. The composition of claim 1, wherein the fluoropolymer is an
amorphous, curable fluoropolymer.
6. The composition of claim 1, wherein the fluoropolymer comprises
at least one of choro, bromo, iodo, or cyano cure sites.
7. The composition of claim 1, further comprising a peroxide
initiator.
8. The composition of claim 1, further comprising at least one of
tri(methyl)allyl isocyanurate, triallyl isocyanurate,
tri(methyl)allyl cyanurate, poly-triallyl isocyanurate,
xylylene-bis(diallyl isocyanurate), N,N'-m-phenylene bismaleimide,
diallyl phthalate, tris(diallylamine)-s-triazine, triallyl
phosphite, diallyl ether of glycerin, triallylphosphate, diallyl
adipate, diallylmelamine, 1,2-polybutadiene, ethyleneglycol
diacrylate, diethyleneglycol diacrylate, or
CH.sub.2.dbd.CH--R.sub.f1--CH.dbd.CH.sub.2, wherein R.sub.f1 is a
perfluoroalkylene having from 1 to 8 carbon atoms.
9. An article comprising a first composition comprising a
fluoropolymer in contact with a second composition comprising a
silicone, wherein at least one of the first composition or second
composition comprises a branched silsesquioxane polymer comprising
terminal --Si(R.sup.3).sub.3 groups and units represented by
formula: ##STR00018## wherein * represents a bond to another
silicon atom in the branched silsesquioxane polymer; each R is
independently an organic group comprising an aliphatic
carbon-carbon double bond; and each R.sup.3 is independently a
non-hydrolyzable group with the proviso that one R.sup.3 may be
hydrogen.
10. The article of claim 9, wherein the branched silsesquioxane
polymer further comprises units represented by formula:
##STR00019## wherein. * represents a bond to another silicon atom
in the branched silsesquioxane polymer; and each R.sup.2 is
independently hydrogen, alkyl, aryl, or alkylene at least one of
interrupted or terminated by arylene or heterocyclylene, wherein
alkyl and alkylene at least one of interrupted or terminated by
arylene or heterocyclylene are unsubstituted or substituted with
halogen and optionally interrupted by at least one catenated --O--,
and wherein aryl, arylene, and heterocyclylene are unsubstituted or
substituted by at least one alkyl, alkoxy, halogen, or combination
thereof.
11. The article of claim 9 or 10, wherein each R is independently
represented by --Y--Z, wherein Y is a bond, alkylene, arylene, or
alkylene at least one of interrupted or terminated by arylene, and
wherein Z is --CH.dbd.CH.sub.2, --CH.sub.2--CH.dbd.CH.sub.2,
--O--CH.dbd.CH.sub.2, --O--C(O)--CH.dbd.CH.sub.2,
--O--C(O)--C(CH.sub.3).dbd.CH.sub.2, --NR'--C(O)--CH.dbd.CH.sub.2,
or --NR'--C(O)--C(CH.sub.3).dbd.CH.sub.2, wherein R' is hydrogen or
alkyl having up to four carbon atoms, or --Y--Z is
--CH.sub.2--CH.dbd.CH.sub.2, and wherein each R.sup.3 is
independently alkyl having up to four carbon atoms.
12. The article of claim 9, wherein the fluoropolymer is an
amorphous, curable fluoropolymer.
13. The article of claim 9, wherein the fluoropolymer comprises at
least one of choro, bromo, iodo, or cyano cure sites.
14. An article comprising a fluoropolymer crosslinked with a
branched silsesquioxane polymer comprising terminal
--Si(R.sup.3).sub.3 groups and units represented by formula:
##STR00020## wherein * represents a bond to another silicon atom in
the branched silsesquioxane polymer; each R* is independently an
organic group comprising a carbon-carbon bond between the branched
silsesquioxane polymer and the fluoropolymer or another R* group in
the branched silsesquioxane polymer; and each R.sup.3 is
independently a non-hydrolyzable group with the proviso that one
R.sup.3 may be hydrogen.
15. An article comprising a fluoropolymer in contact with a
silicone, wherein at least one of the fluoropolymer or the silicone
is crosslinked with a branched silsesquioxane polymer comprising
terminal -Si(R.sup.3)3 groups and units represented by formula:
##STR00021## wherein * represents a bond to another silicon atom in
the branched silsesquioxane polymer; each R* is independently an
organic group comprising a carbon-carbon bond between the branched
silsesquioxane polymer and the fluoropolymer, the silicone, or
another R* group in the branched silsesquioxane polymer; and each
R.sup.3 is independently a non-hydrolyzable group with the proviso
that one R.sup.3 may be hydrogen.
16. The composition of claim 1, further comprising a
non-fluorinated, curable polymer.
17. The composition of claim 16, wherein the non-fluorinated,
curable polymer is an ethylene-propylene-diene or a silicone.
18. The composition of claim 2, wherein each R.sup.2 is
independently unsubstituted alkyl or alkyl substituted by
fluoro.
19. The composition of claim 1, wherein Y is a bond or
--CH.sub.2--, and wherein Z is --CH.dbd.CH.sub.2.
20. The article of claim 9, wherein the silicone is a curable
polydimethysiloxane.
Description
BACKGROUND
[0001] Fluoroelastomers are known to have excellent mechanical
properties, heat resistance, weather resistance, and chemical
resistance, for example. Such beneficial properties render
fluoroelastomers useful for example, as O-rings, seals, hoses, skid
materials, and coatings (e.g., metal gasket coating for
automobiles). Fluoroelastomers have been found useful in the
automotive, chemical processing, semiconductor, aerospace, and
petroleum industries, among others.
[0002] Fluoroelastomers are typically prepared by combining an
amorphous fluoropolymer, sometimes referred to as a fluoroelastomer
gum, with one or more curatives, shaping the resulting curable
composition into a desired shape, and curing the curable
composition. The amorphous fluoropolymer often includes a cure
site, which is a functional group incorporated into the amorphous
fluoropolymer backbone capable of reacting with a certain
curative.
[0003] Certain reactive silicon-containing compounds have been
added to curable fluoropolymer compounds. See, for example, U.S.
Pat. Appl. Pub. No 2017/0263908 (Laicer et al.) and Int. Pat. Appl.
Pub. No. WO 2019/133410 (Mitchell et al.).
SUMMARY
[0004] The present disclosure provides compositions and articles
that include a fluoropolymer that can include or is at least
partially crosslinked with a branched silsesquioxane polymer.
Typically, when the branched silsesquioxane polymer is used to
crosslink a fluoropolymer to make a fluorolastomer, the tear
resistance of the fluoroelastomer is higher than when a comparative
fluoroelastomer is made in the absence of the branched
silsesquioxane polymer. Typically and unexpectedly,
fluoroelastomers crosslinked with the branched silsesquioxane
polymer have much lower compression set than fluoroealstomers
crosslinked with polysiloxanes including aliphatic carbon-carbon
double bonds.
[0005] In one aspect, the present disclosure provides a composition
that includes a fluoropolymer and a branched silsesquioxane polymer
having terminal --Si(R.sup.3).sub.3 groups and units represented by
formula:
##STR00001##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer, each R is independently an organic
group including an aliphatic carbon-carbon double bond, and each
R.sup.3 is independently a non-hydrolyzable group with the proviso
that one R.sup.3 may be hydrogen.
[0006] In another aspect, the present disclosure provides an
article that includes a first composition including a fluoropolymer
in contact with a second composition including a silicone. At least
one of the first composition or second composition includes a
branched silsesquioxane polymer having terminal --Si(R.sup.3).sub.3
groups and units represented by formula:
##STR00002##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer, each R is independently an organic
group including an aliphatic carbon-carbon double bond, and each
R.sup.3 is independently a non-hydrolyzable group with the proviso
that one R.sup.3 may be hydrogen.
[0007] In another aspect, the present disclosure provides article
including a fluoropolymer crosslinked with a branched
silsesquioxane polymer having terminal --Si(R.sup.3).sub.3 groups
and units represented by formula:
##STR00003##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer, each R* is independently an
organic group including a carbon-carbon bond between the branched
silsesquioxane polymer and the fluoropolymer or another R* group in
the branched silsesquioxane polymer, and each R.sup.3 is
independently a non-hydrolyzable group with the proviso that one
R.sup.3 may be hydrogen.
[0008] In another aspect, the present disclosure provides an
article including a fluoropolymer in contact with a silicone. At
least one of the fluoropolymer or the silicone is crosslinked with
a branched silsesquioxane polymer having terminal
--Si(R.sup.3).sub.3 groups and units represented by formula:
##STR00004##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer, each R* is independently an
organic group including a carbon-carbon bond between the branched
silsesquioxane polymer and the fluoropolymer, the silicone, or
another R* group in the branched silsesquioxane polymer, and each
R.sup.3 is independently a non-hydrolyzable group with the proviso
that one R.sup.3 may be hydrogen.
[0009] In this application:
[0010] Terms such as "a", "an" and "the" are not intended to refer
to only a singular entity but include the general class of which a
specific example may be used for illustration. The terms "a", "an",
and "the" are used interchangeably with the term "at least
one".
[0011] The phrase "comprises at least one of" followed by a list
refers to comprising any one of the items in the list and any
combination of two or more items in the list. The phrase "at least
one of" followed by a list refers to any one of the items in the
list or any combination of two or more items in the list.
[0012] The term "aliphatic" refers to being non-aromatic. This term
is used to encompass alkyl, alkenyl, and alkynyl groups, for
example.
[0013] The term "alkyl" refers to a monovalent group that is a
radical of an alkane and includes straight-chain, branched, cyclic,
and bicyclic alkyl groups, and combinations thereof, including both
unsubstituted and substituted alkyl groups. Unless otherwise
indicated, the alkyl groups typically contain from 1 to 30 carbon
atoms. In some embodiments, the alkyl groups contain 1 to 20 carbon
atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon
atoms, or 1 to 3 carbon atoms. Cyclic groups can be monocyclic or
polycyclic and typically have from 3 to 10 ring carbon atoms.
Examples of "alkyl" groups include methyl, ethyl, n-propyl,
n-butyl, n-pentyl, isobutyl, t-butyl, isopropyl, n-octyl, n-heptyl,
ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, and
norbornyl.
[0014] The term "alkylene" is the divalent or trivalent form of the
"alkyl" groups defined above.
[0015] The term "aryl" refers to a monovalent group that is
aromatic and, optionally, carbocyclic. The aryl has at least one
aromatic ring. Any additional rings can be unsaturated, partially
saturated, saturated, or aromatic. Optionally, the aromatic ring
can have one or more additional carbocyclic rings that are fused to
the aromatic ring. Unless otherwise indicated, the aryl groups
typically contain from 6 to 30 carbon atoms and optionally contain
at least one heteroatom (i.e., O, N, or S). In some embodiments,
the aryl groups contain 6 to 20, 6 to 18, 6 to 16, 6 to 12, or 6 to
10 carbon atoms. Examples of an aryl group include phenyl,
naphthyl, biphenyl, phenanthryl, anthracyl, and pyridinyl.
[0016] The term "arylene" is the divalent form of the "aryl" groups
defined above.
[0017] The terms "cure" and "curable" joining polymer chains
together by covalent chemical bonds, usually via crosslinking
molecules or groups, to form a network polymer. Therefore, in this
disclosure the terms "cured" and "crosslinked" may be used
interchangeably. A cured or crosslinked polymer is generally
characterized by insolubility but may be swellable in the presence
of an appropriate solvent.
[0018] The term "catenated heteroatom" means an atom other than
carbon (for example, oxygen, nitrogen, or sulfur) that replaces one
or more carbon atoms in a carbon chain (for example, so as to form
a carbon-heteroatom-carbon chain or a
carbon-heteroatom-heteroatom-carbon chain).
[0019] The phrase "interrupted by at least one --O-- group", for
example, with regard to a perfluoroalkyl or perfluoroalkylene group
refers to having part of the perfluoroalkyl or perfluoroalkylene on
both sides of the --O-- group. For example,
--CF.sub.2CF.sub.2--O--CF.sub.2--CF.sub.2-- is a perfluoroalkylene
group interrupted by an --O--.
[0020] The term "(meth)acrylate group" is a functional group that
refers to an acrylate group of the formula CH.sub.2.dbd.CH--C(O)O--
and a methacrylate group of the formula
CH.sub.2.dbd.C(CH.sub.3)--C(O)O--.
[0021] The term "halogen" refers to a halogen atom or one or more
halogen atoms, including chlorine, bromine, iodine, and fluorine
atoms or fluoro, chloro, bromo, or iodo substituents.
[0022] The term "fluoro-" (for example, in reference to a group or
moiety, such as in the case of "fluoroalkylene" or "fluoroalkyl" or
"fluorocarbon") or "fluorinated" can mean partially fluorinated
such that there is at least one carbon-bonded hydrogen atom or
perfluorinated.
[0023] The term "perfluoro-" (for example, in reference to a group
or moiety, such as in the case of "perfluoroalkylene" or
"perfluoroalkyl" or "perfluorocarbon") or "perfluorinated" means
completely fluorinated such that, except as may be otherwise
indicated, there are no carbon-bonded hydrogen atoms replaceable
with fluorine.
[0024] The term "perfluoroether" means a group or moiety having two
saturated or unsaturated perfluorocarbon groups (linear, branched,
cyclic (preferably, alicyclic), or a combination thereof) linked
with an oxygen atom (that is, there is at least one catenated
oxygen atom).
[0025] The term "polyfluoropolyether" means a group having three or
more saturated or unsaturated perfluorocarbon groups (linear,
branched, cyclic (preferably, alicyclic), or a combination thereof)
linked with oxygen atoms (that is, there are at least two catenated
oxygen atoms).
[0026] A silsesquioxane is an organosilicon compound with the
empirical chemical formula R'SiO3/2 where Si is the element
silicon, O is oxygen and R' is either hydrogen or an aliphatic or
aromatic organic group that optionally further comprises an
ethylenically unsaturated group. Thus, silsesquioxanes polymers
comprise silicon atoms bonded to three oxygen atoms.
Silsesquioxanes polymers that have a random branched structure are
typically liquids at room temperature. Silsesquioxanes polymers
that have a non-random structure like cubes, hexagonal prisms,
octagonal prisms, decagonal prisms, and dodecagonal prisms are
typically solids as room temperature. The branched silsesquioxane
polymers in the compositions and articles of the present disclosure
exclude cage structures (e.g., cubes, hexagonal prisms, octagonal
prisms, decagonal prisms, and dodecagonal prisms).
[0027] All numerical ranges are inclusive of their endpoints and
nonintegral values between the endpoints unless otherwise stated
(e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a depiction of the structure of an embodiment of
the branched silsesquioxane polymer useful in the compositions and
articles of the present disclosure.
[0029] FIG. 2 is a schematic side view of an embodiment of an
article of the present disclosure.
[0030] FIG. 3 is a perspective side of another embodiment of an
article of the present disclosure.
DETAILED DESCRIPTION
[0031] The branched silsesquioxane polymer useful in the
compositions and articles of the present disclosure includes
terminal --Si(R.sup.3).sub.3 groups and units represented by
formula
##STR00005##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer, and each R is independently an
organic group comprising an aliphatic carbon-carbon double bond.
Each R.sup.3 in the terminal groups is independently a
non-hydrolyzable group with the proviso that one R.sup.3 may be
hydrogen.
[0032] In some embodiments, each R is independently represented by
--Y--Z, wherein Y is a bond, alkylene, arylene, or alkylene at
least one of interrupted or terminated by arylene, wherein alkylene
and alkylene at least one of interrupted or terminated by arylene
are unsubstituted or substituted with halogen and optionally
interrupted by at least one catenated --O--, --NR'--, --S--,
--Si--, or combination thereof, and wherein arylene is
unsubstituted or substituted by at least one alkyl, alkoxy,
halogen, or combination thereof, wherein R' is hydrogen or alkyl
having up to four carbon atoms. In some embodiments, Y is a bond,
an alkylene group having from 1 to 20, 1 to 6, 1 to 4, 1 to 3, 1 to
2, or 1 carbon atom, phenylene, or an alkylene group having from 1
to 6, 1 to 4, or 1 to 3 carbon atoms interrupted by phenylene
(e.g., methylphenylpropyl). In formula --Y--Z, Z is vinyl (i.e.,
--CH.dbd.CH.sub.2), vinyl ether (i.e., --O--CH.dbd.CH.sub.2),
acryloyloxy (i.e., --O--C(O)--CH.dbd.CH.sub.2), methacryloyloxy
(i.e., --O--C(O)--C(CH.sub.3).dbd.CH.sub.2), acryloylamino (i.e.,
--NR'--C(O)--CH.dbd.CH.sub.2 wherein R' is hydrogen or alkyl having
up to four carbon atoms), or methacryloylamino group (i.e.,
--NR'--C(O)--C(CH.sub.3).dbd.CH.sub.2, wherein R' is hydrogen or
alkyl having up to four carbon atoms). When Y is alkylene and Z is
a vinyl group, Y-Z is an alkenyl group. Such alkenyl group may have
the formula (H.sub.2C.dbd.CH(CH.sub.2).sub.y-- wherein y is 1 to
20, 1 to 6, 1 to 4, 1 to 3, 1 to 2, or 1). The alkylene group can
be 3-butenyl, docosenyl, or hexenyl, for example. In some
embodiments, --Y--Z is allyl (i.e.,
--CH.sub.2--CH.dbd.CH.sub.2).
[0033] Fluoropolymers and/or silicones described in further detail
below can be crosslinked with the branched silsesquioxane polymer,
and the resulting network can have units represented by formula
##STR00006##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer; and each R* is independently an
organic group comprising a carbon-carbon bond between the branched
silsesquioxane polymer and the fluoropolymer, silicone, or another
R* group in the branched silsesquioxane polymer. Upon crosslinking,
in the R group in the branched silsesquioxane polymer, described
above, the aliphatic carbon-carbon double bond reacts to form the
R* group. In embodiments in which the R group is represented by
--Y--Z, R* may consist of the carbon-carbon bond between the
branched silsesquioxane polymer and the fluoropolymer, silicon, or
another R* group, or R* can optionally further include alkylene,
arylene, or alkylene at least one of interrupted or terminated by
arylene, --O--, --NR'--, --O--C(O)--, --NR'--C(O)--, --S--, --Si--,
or a combination thereof, wherein R' is hydrogen or alkyl having up
to four carbon atoms, and optionally substituted by halogen and, in
the case of arylene, optionally substituted by alkyl or alkoxy. In
some embodiments, R* is the carbon-carbon bond optionally bonded to
--(CH.sub.2).sub.y--, wherein y is 1 to 6, 1 to 4, 1 to 3, 1 to 2,
or 1.
[0034] In some embodiments, the branched silsesquioxane polymer
useful in the compositions and articles of the present disclosure
includes units represented by formula:
##STR00007##
In this formula, * represents a bond to another silicon atom in the
branched silsesquioxane polymer, and each R.sup.2 is independently
a hydrogen or non-hydrolyzable group not comprising an aliphatic
carbon-carbon double bond. As stated above, each R.sup.3 in the
terminal groups is independently a non-hydrolyzable group with the
proviso that one R.sup.3 may be hydrogen.
[0035] Suitable non-hydrolyzable groups useful as R.sup.2 and
R.sup.3 substituents include alkyl, aryl, alkylene at least one of
interrupted or terminated by arylene or heterocyclylene, wherein
alkyl and alkylene at least one of interrupted or terminated by
arylene or heterocyclylene are unsubstituted or substituted with
halogen and optionally interrupted by at least one catenated --O--,
--NR'--, --S--, --Si--, or combination thereof, and wherein aryl,
arylene, and heterocyclylene are unsubstituted or substituted by at
least one alkyl, alkoxy, halogen, or combination thereof. R.sup.2
and R.sup.3 non-hydrolyzable groups are selected independently from
each other.
[0036] In some embodiments, the halogen or halogens on the alkyl,
alkylene, arylene, or heterocyclylene group is fluoro. When at
least one of R.sup.2 or R.sup.3 is fluorinated, in some
embodiments, at least one of R.sup.2 or R.sup.3 is
R.sub.fC.sub.jH.sub.2j--, wherein j is 2 to 8 (or 2 to 3), and
R.sub.f is a fluorinated or perfluorinated alkyl group having 1 to
12 carbon atoms (or 1 to 6 carbon atoms); in some embodiments, at
least one of R.sup.2 or R.sup.3 is R.sub.f'C.sub.jH.sub.2j--,
wherein j is 2 to 8 (or 2 to 3), and R.sub.f' is a fluorinated or
perfluorinated polyether group having 1 to 45 carbon atoms (in some
embodiments, 1 to 30 carbon atoms). Perfluoropolyether groups that
can be linear, branched, cyclic, or a combination thereof. The
perfluoropolyether group can be saturated or unsaturated (in some
embodiments, saturated). Examples of useful perfluoropolyether
groups include those that have --(C.sub.pF.sub.2p)--,
--(C.sub.pF.sub.2pO)--, --(CF(RF)O)--,
--(CF(RF)C.sub.pF.sub.2pO)--, --(C.sub.pF.sub.2pCF(RF)O)--, or
--(CF.sub.2CF(RF)O)-- repeating units or combinations thereof,
wherein p is an integer of 1 to 10 (or 1 to 8, or 1 to 6, or 1 to
4, or 1 to 3); RF is selected from perfluoroalkyl, perfluoroether,
perfluoropolyether, and perfluoroalkoxy groups that are linear,
branched, cyclic, or a combination thereof and that have up to 12
carbon atoms, up to 10 carbon atoms, up to 8 carbon atoms, up to 6
carbon atoms, up to 4 carbon atoms, or up to 3 carbon atoms) and/or
up to 4 oxygen atoms, up to 3 oxygen atoms, up to 2 oxygen atoms,
or zero or one oxygen atom. In these perfluoropolyether structures,
different repeating units can be combined in a block, alternating,
or random arrangement to form the perfluoropolyether group. The
terminal group of the perfluoropolyether group can be
(C.sub.pF.sub.2p+1)-- or (C.sub.pF.sub.2p+1O)--, for example,
wherein p is as defined above. Examples of useful
perfluoropolyether groups include
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.n--CF(CF.sub.3)--,
C.sub.3F.sub.7O(CF.sub.2CF.sub.2CF.sub.2O)--CF.sub.2CF.sub.2--,
CF.sub.3O(C.sub.2F.sub.4O).sub.n--CF.sub.2--,
CF.sub.3O(CF.sub.2O).sub.n--C.sub.2F.sub.4O).sub.qCF.sub.2--, and
F(CF.sub.2).sub.3O(C.sub.3F.sub.6O).sub.q(CF.sub.2).sub.3--,
wherein n'' has an average value of 0 to 50, or 1 to 50, or 3 to
30, or 3 to 15, or 3 to 10; and q has an average value of 0 to 50,
or 3 to 30, or 3 to 15, or 3 to 10. In some embodiments, the
perfluoropolyether group comprises at least one divalent
hexafluoropropyleneoxy group (--CF(CF.sub.3)--CF.sub.2O--).
Perfluoropolyether groups can include
F[CF(CF.sub.3)CF.sub.2O].sub.aCF(CF.sub.3)-- (or, as represented
above, C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.n--CF(CF.sub.3),
where n''+1=a), wherein a has an average value of 4 to 20. Such
perfluoropolyether groups can be obtained through the
oligomerization of hexafluoropropylene oxide.
[0037] In some embodiments, each R.sup.3 is independently hydrogen,
alkyl, aryl, or alkyl substituted by fluoro and optionally
interrupted by at least one catenated --O-- group. Typically, only
one R.sup.3 is hydrogen. Suitable alkyl groups for R.sup.3
typically have 1 to 20, 1 to 18, 1 to 12, 1 to 10, 1 to 6, or 1 to
4 carbon atoms. Examples of useful alkyl groups include methyl,
ethyl, isopropyl, n-propyl, n-butyl, and iso-butyl. In some
embodiments, each R.sup.3 is independently alkyl having up to six
(in some embodiments, up to 4, 3, or 2) carbon atoms,
F[CF(CF.sub.3)CF.sub.2O].sub.aCF(CF.sub.3)C.sub.jH.sub.2j--
(wherein j 2 to 8 (or 2 to 3) and a has an average value of 4 to
20), C.sub.4F.sub.9C.sub.3H.sub.6--,
C.sub.4F.sub.9C.sub.2H.sub.4--, C.sub.4F.sub.9OC.sub.3H.sub.6--,
C.sub.6F.sub.13C.sub.3H.sub.6--, C.sub.6F.sub.13C.sub.2H.sub.4--,
CF.sub.3C.sub.3H.sub.6--, CF.sub.3C.sub.2H.sub.4--, phenyl, benzyl,
or C.sub.6H.sub.5C.sub.2H.sub.4--. In some embodiments, each
R.sup.3 is independently methyl or phenyl. In some embodiments,
each R.sup.3 is methyl.
[0038] In some embodiments, each R.sup.2 is independently hydrogen,
alkyl, aryl, or alkyl substituted by fluoro and optionally
interrupted by at least one catenated --O-- group. Suitable alkyl
groups for R.sup.2 typically have 1 to 20, 1 to 18, 1 to 12, 1 to
10, 1 to 6, or 1 to 4 carbon atoms. Examples of useful alkyl groups
include methyl, ethyl, isopropyl, n-propyl, n-butyl, iso-butyl, and
octadecyl. In some embodiments, each R.sup.2 is independently alkyl
having up to 18 (in some embodiments, up to 4, 3, or 2) carbon
atoms, F[CF(CF.sub.3)CF.sub.2O].sub.aCF(CF.sub.3)C.sub.jH.sub.2j--
(wherein j is 2 to 8 (or 2 to 3) and a has an average value of 4 to
20), C.sub.4F.sub.9C.sub.3H.sub.6--,
C.sub.4F.sub.9C.sub.2H.sub.4--, C.sub.4F.sub.9OC.sub.3H.sub.6--,
C.sub.6F.sub.13C.sub.3H.sub.3--, C.sub.6F.sub.13C.sub.2H.sub.4--,
CF.sub.3C.sub.3H.sub.6--, CF.sub.3C.sub.2H.sub.4--, phenyl, benzyl,
or C.sub.6H.sub.5C.sub.2H.sub.4--. In some embodiments, each
R.sup.2 is independently methyl, phenyl,
C.sub.6F.sub.13C.sub.2H.sub.4--, or octadecyl.
[0039] In some embodiments, the branched silsesquioxane polymer
useful in the compositions and articles of the present disclosure
is represented by formula:
##STR00008##
wherein *, R, and R.sup.3 are independently as defined above in any
of their embodiments, and wherein n is at least 2. In some
embodiments, n is at least 3, 4, 5, 6, 7, 8 or 9.
[0040] In some embodiments, the branched silsesquioxane polymer
useful in the compositions and articles of the present disclosure
is represented by formula:
##STR00009##
wherein *, R, R.sup.2, and R.sup.3 are independently as defined
above in any of their embodiments, and n+m is greater than 3.
Although this formula is shown as a block copolymer, it should be
understood that the divalent units including R and R.sup.2 can be
randomly positioned in the copolymer. Thus, branched silsesquioxane
polymers useful for practicing the present disclosure also include
random copolymers. In some embodiments, m is at least 1, 2, 3, 4,
5, 6, 7, 8, 9 and the sum of n+m is 3 or greater than 3. In some
embodiments, n, m, or n+m is at least 10, 15, 20, 25, 30, 35, 40,
45, or 50. In some embodiments, n or m is not more than 500, 450,
400, 350, 300, 250, or 200. Thus, n+m can range up to 1000. In some
embodiments, n+m is an integer of not more than 175, 150, or 125.
In some embodiments, n and m are selected such the copolymer
comprises at least 25, 26, 27, 28, 29, or 30 mol % of repeat units
including R groups. In some embodiments, n and m are selected such
the copolymer comprises not more than 85, 80, 75, 70, 65, or 60 mol
% of repeat units including R groups.
[0041] In some embodiments, each R is vinyl. In one naming
convention, the R.sup.3 group is included in the name of the
polymer. An example of a branched silsesquioxane polymer end-capped
with ethoxytrimethylsilane is trimethyl silyl
poly(vinylsilsesquioxane). The three-dimensional branched network
structure of this polymer can be depicted as shown in FIG. 1.
[0042] In some embodiments, R is Y-Z, wherein Y-Z is allyl,
allylphenylpropyl, 3-butenyl, docosenyl, or hexenyl, and the
branched silsesquioxane polymer is trimethylsilyl
poly(allylsilsesquioxane). trimethylsilyl
poly(allylphenylpropylsilsesquioxane), trimethylsilyl
poly(3-butenylsilsesquioxane), trimethylsilyl poly(docosenyl
silsesquioxane), or trimethylsilyl poly(hexenylsilsesquioxane).
Examples of other useful branched silsesquioxane polymers include
trimethylsilyl vinyl-co-(perfluorohexyl)ethyl silsequioxane,
trimethylsilyl vinyl-co-phenyl silsesquioxane, trimethylsilyl
vinyl-co-methyl silsesquioxane, trimethylsilyl vinyl-co-octadecyl
silsesquioxane, trimethylsilyl vinyl-co-hydro silsesquioxane,
trimethylsilyl allyl-co-(perfluorohexyl)ethyl silsequioxane,
trimethylsilyl allyl-co-phenyl silsesquioxane, trimethylsilyl
allyl-co-methyl silsesquioxane, trimethylsilyl allyl-co-octadecyl
silsesquioxane, and trimethyl silyl allyl-co-hydro
silsesquioxane.
[0043] In some embodiments, the branched silsesquioxane polymer
useful in the compositions and methods of the present disclosure is
free of hydrolyzed groups such as --OH group. In some embodiments,
the number of hydrolyzed groups (e.g. --OH groups) is not more than
15, 10, or 5 wt. %. In some embodiments, the number of hydrolyzed
groups (e.g. --OH groups) is not more than 4, 3, 2 or 1 wt. %. The
branched silsesquioxane polymer and compositions of the present
disclosure can exhibit improved shelf life and thermal stability in
comparison to silsesquioxane polymers having higher concentrations
of --OH groups.
[0044] The branched silsesquioxane polymer useful in the
compositions and articles of the present disclosure can be prepared
by hydrolysis and condensation of a compound having the formula
R--Si(R.sup.1).sub.3 and optionally a compound having the formula
R.sup.2--Si(R.sup.1).sub.3, wherein R and R.sup.2 are as defined
above in any of their embodiments, and R.sup.1 is a hydrolyzable
group. The term "hydrolyzable group" refers to a group that can
react with water under conditions of atmospheric pressure. The
reaction with water may optionally be catalyzed by acid or base.
Suitable hydrolyzable groups include halogen (e.g., iodo, bromo,
chloro); alkoxy (e.g., --O-alkyl), aryloxy (e.g., --O--aryl),
acyloxy (e.g., --O--C(O)-alkyl), amino (e.g.,
--N(R.sup.A)(R.sup.B), wherein each R.sup.A or R.sup.B is
independently hydrogen or alkyl), polyalkyleneoxy; and oxime (e.g.,
--O--N.dbd.C--(R.sup.1)(R.sup.2). In some embodiments, each R.sup.1
is independently halogen or alkoxy optionally substituted by
halogen. In some embodiments, each R.sup.1 is independently chloro
or alkoxy having up to 12 (or up to 6 or 4) carbon atoms. In some
embodiments, each R.sup.1 is independently methoxy or ethoxy.
[0045] When the compounds of formula R--Si(R.sup.1).sub.3 and
optionally R.sup.2--Si(R.sup.1).sub.3 react, R.sup.1 is converted
to a hydrolyzed group, such as --OH, during hydrolysis. The Si--OH
groups react with each other to form silicone-oxygen linkages such
that the majority of silicon atoms are bonded to three oxygen
atoms. After hydrolysis, the --OH groups are further reacted with
an end-capping agent to convert the hydrolyzed group, e.g. --OH, to
--OSi(R.sup.3).sub.3. Suitable end-capping agents include those
having formulas R.sup.1--Si(R.sup.3).sub.3 and
O[Si(R.sup.3).sub.3].sub.2, for example. The silsesquioxane polymer
comprises terminal groups having the formula --Si(R.sup.3).sub.3
wherein R.sup.3 is as defined above in any of its embodiments,
after end-capping. Hydrolysis and condensation can be carried out
by conventional methods, for example, by heating the compound of
formula R--Si(R.sup.1).sub.3 and optionally
R.sup.2--Si(R.sup.1).sub.3 in water optionally in the presence of
acid or base. Further details and methods can be found in the
Examples, below.
[0046] Examples of readily available compounds of formula
R--Si(R.sup.1).sub.3 include vinyltriethoxysilane,
vinyltrimethoxysilane, allyltriethoxysilane, allyltrimethoxysilane,
allylphenylpropyltriethoxysilane, 3-butenyltriethoxysilane,
docosenyltriethoxysilane, and hexenyltriethoxysilane. Examples of
readily available end-capping agents having formulas
R.sup.1--Si(R.sup.3).sub.3 and O[Si(R.sup.3).sub.3].sub.2 include
n-butyldimethylmethoxysilane, t-butyldiphenylmethoxysilane,
3-chloroisobutyldimethylmethoxysilane, phenyldimethylethoxysilane,
n-propyldimethylmethoxysilane, triethylethoxysilane,
trimethylmethoxysilane, triphenylethoxysilane,
n-octyldimethylmethoxysilane, hexamethyldisiloxane,
hexaethyldisiloxane, 1,1,1,3,3,3-hexaphenyldisiloxane,
1,1,1,3,3,3-hexakis(4-(dimethylamino)phenyl)disiloxane, and
1,1,1,3,3,3-hexakis(3-fluorobenzyl)disiloxane.
[0047] In some embodiments, branched silsesquioxane copolymers can
be made with two or more reactants of the formula
R--Si(R.sup.1).sub.3. For example, vinyltriethoxylsilane or
allytriethoxysilane can be coreacted with an alkenylalkoxylsilane
such as 3-butenyltriethoxysilane and hexenyltriethoxysilane. In
this embodiment, the branched silsesquioxane polymers in which R is
--Y--Z as described above includes the same Z group (i.e.,
--CH.dbd.CH.sub.2) and different Y groups (e.g., a bond or
--CH.sub.2--, C.sub.2H.sub.4--, or --C.sub.4H.sub.8--). In some
embodiments, the branched silsesquioxane polymer can comprise at
least two different Z groups and the same Y group. In some
embodiments, the branched silsesquioxane polymer comprises at least
two reactants wherein both Y and Z are different than each
other.
[0048] In some embodiments, curable silsesquioxane copolymers can
be made with at least one reactant of the formula
R--Si(R.sup.1).sub.3 and at least one reactant of the formula
R.sup.2--Si(R.sup.1).sub.3. Examples of reactants of the formula
R.sup.2--Si(R.sup.1).sub.3 include aromatic trialkoxysilanes (e.g.,
phenyltrimethoxylsilane), alkyl trialkoxysilanes (e.g.,
methyltrimethoxylsilane and octadecyltrimethoxysilane), and
fluoroalkyl trialkoxysilanes (e.g., nonafluorohexyltriethoxysilane
and perfluorohexylethyl trimethoxysilane). Other commercially
available R.sup.2--Si(R.sup.1).sub.3 reactants include
trimethylsiloxytriethoxysilane; p-tolyltriethoxysilane;
n-propyltriethoxysilane; (4-perfluorooctylphenyl)triethoxysilane;
pentafluorophenyltriethoxysilane;
nonafluorohexyltriethoxysilane;1-naphthyltriethoxysilane;
3,4-methylenedioxyphenyltriethoxysilane;
p-methoxyphenyltriethoxysilane; 3-isooctyltriethoxysilane;
isobutyltriethoxysilane;(heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethox-
ysilane; 3,5-dimethoxyphenyltriethoxysilane;
11-chloroundecyltriethoxysilane; 3-chloropropyltriethoxysilane;
p-chlorophenyltriethoxysilane; chlorophenyltriethoxysilane;
benzyltriethoxysilane; and
2-[(acetoxy(polyethyleneoxy)propyl]triethoxysilane.
[0049] The inclusion of the co-reactant of the formula
R.sup.2--Si(R.sup.1).sub.3 can be useful for enhancing certain
properties depending on the selection of the R.sup.2 group. For
example, when R.sup.2 comprises an aromatic group such as phenyl,
the thermal stability of the branched silsesquioxane polymer can be
improved (relative to a homopolymer of vinyltrimethoxysilane).
Further, when R.sup.2 comprises a fluoroalkyl group, the
hydrophobicity can be improved relative to silsesquioxane polymers
that do not include fluoroalkyl groups.
[0050] The amount of reactant(s) of the formula
R--Si(R.sup.1).sub.3 can range up to 100 mol % in the case of
homopolymers, before the endcapping step. The copolymers typically
comprise up to 99, 98, 97, 96, 95, 94, 93, 92, 91, or 90 mol % of
reactant(s) of the formula R--Si(R.sup.1).sub.3. In some
embodiments, the amount of reactant(s) of the formula
R--Si(R.sup.1).sub.3 is up to 85, 80, 75, 70, or 60 mol %. In some
embodiments, the amount of reactant(s) of the formula
R--Si(R.sup.1).sub.3 is at least 15, 20, 25, or 30 mol %. When
present, the amount of reactant(s) of the formula
R.sup.2--Si(R.sup.1).sub.3 can be at least 1, 2, 3, 4, 5, 6, 7, 8,
9, or 10 mol % of the copolymer. The amount of reactant(s) of the
formula R.sup.2--Si(R.sup.1).sub.3 is typically up to 75 mol % or
70 mol %. In some embodiments, the amount of reactant(s) of the
formula R.sup.2--Si(R.sup.1).sub.3 is at least 15, 20, 25, or 30
mol %. In some embodiments, the amount of reactant(s) of the
formula R.sup.2--Si(R.sup.1).sub.3 is up to 65 or 60 mol %. In some
embodiments, the molar ratio of reactant(s) of the formula
R--Si(R.sup.1).sub.3 to molar ratio to reactant(s) of the formula
R.sup.2--Si(R.sup.1).sub.3 ranges from about 15:1 or 10:1 to 1:4,
or 1:3, or 1:2.
[0051] For more information about branched silsesquioxane polymers
useful for practicing the present disclosure and the method of
making them, see, for example, U.S. Pat. No. 10,066,123 (Rathore et
al.).
[0052] Useful branched silsesquioxane polymers can have a wide
variety of viscosities. Viscosity correlates with molecular weight,
that is, it increases with increasing molecular weight. The
viscosity of the branched silsesquioxane polymer useful in the
compositions and articles of the present disclosure may be up to
50,000 centipoise (cps), 40,000 cps, 30,000 cps, 25,000 cps, 20,000
cps, 15,000 cps, 10,000 cps, 9,000 cps, 8,000 cps, 7,000 cps, 6,000
cps, 5,000 cps, 4,000 cps, or 3,000 cps as measured on a Brookfield
DV-II+ Viscometer with the LV4 spindle. The viscosity of the
branched silsesquioxane polymer useful in the compositions and
articles of the present disclosure may be at least 100 cps, 200
cps, 300 cps, 400 cps, 500 cps, 600 cps, 700 cps, 800 cps, 900 cps,
or 1,000 cps, as measured on a Brookfield DV-II+ Viscometer with
the LV4 spindle. In some embodiments, the viscosity of the branched
silsesquioxane polymer useful in the compositions and articles of
the present disclosure may be in a range from 500 cps to 15,000
cps, 500 cps to 10,000 cps, 500 cps to 5,000 cps, or 1,000 cps to
3,000 cps.
[0053] The composition of the present disclosure and the first
composition in the article of the present disclosure include at
least one fluoropolymer. In some embodiments, the composition (in
some embodiments, the first composition) contains at least 50% by
weight, at least 75%, at least 80%, at least 90%, or even at least
95% by weight fluoropolymer(s) based on the total weight of the
composition.
[0054] The fluoropolymer useful in the compositions and articles of
the present disclosure may have a partially or fully fluorinated
backbone. Suitable fluoropolymers include those that have a
backbone that is at least 30% by weight fluorinated, at least 50%
by weight fluorinated, and in some embodiments at least 65% by
weight fluorinated; these percentages indicate the weight percent
contributed by fluorine atoms in the fluoropolymer. Fluoropolymers
useful for practicing the present disclosure may include one or
more interpolymerized units derived from at least two principal
monomers. Examples of suitable fluorinated monomers include
perfluoroolefins (e.g., tetrafluoroethylene (TFE) and
hexafluoropropylene (HFP), or any perfluoroolefin of the formula
CF.sub.2.dbd.CF--Rf, where Rf is fluorine or a perfluoroalkyl of 1
to 8, in some embodiments 1 to 3, carbon atoms), perfluorovinyl
ethers (e.g., perfluoroalkyl vinyl ethers (PAVE) and
perfluoroalkoxyalkyl vinyl ethers (PAOVE)), perfluoroallyl ethers
(e.g., perfluoroalkyl allyl ethers and perfluoroalkoxyalkyl allyl
ethers), halogenated fluoroolefins (e.g., trifluorochloroethylene
(CTFE), 2-chloropentafluoropropene, and dichlorodifluoroethylene),
and partially fluorinated olefins (e.g., vinylidene fluoride (VDF),
vinyl fluoride, pentafluoropropylene, and trifluoroethylene).
Suitable non-fluorinated comonomers include vinyl chloride,
vinylidene chloride, and C.sub.2-C.sub.8 olefins (e.g., ethylene
(E) and propylene (P)).
[0055] In some embodiments, the fluoropolymer useful in the
compositions and articles of the present disclosure includes units
from one or more monomers independently represented by formula
CF.sub.2.dbd.CF(CF.sub.2).sub.m(OCF.sub.2F.sub.2n).sub.zOR.sub.f.sup.2,
wherein R.sub.f.sup.2 is a linear or branched perfluoroalkyl group
having from 1 to 8 carbon atoms and uninterrupted or interrupted by
one or more --O-- groups; z is 0, 1, or 2; each n is independently
1, 2, 3, or 4; m is 0 or 1. Suitable monomers of this formula
include those in which m and z are 0, and the perfluoroalkyl
perfluorovinyl ethers are represented by formula
CF.sub.2.dbd.CFOR.sub.f.sup.2, wherein R.sub.f.sup.2 is
perfluoroalkyl having from 1 to 8, 1 to 4, or 1 to 3 carbon atoms,
optionally interrupted by one or more --O-- groups.
Perfluoroalkoxyalkyl vinyl ethers suitable for making a
fluoropolymer include those represented by formula
CF.sub.2.dbd.CF(CF.sub.2).sub.m(OC.sub.nF.sub.2n).sub.zOR.sub.f.sup.2,
in which m is 0, each n is independently from 1 to 6, z is 1 or 2,
and R.sub.f.sup.2 is a linear or branched perfluoroalkyl group
having from 1 to 8 carbon atoms and optionally interrupted by one
or more --O-- groups. In some embodiments, n is from 1 to 4, or
from 1 to 3, or from 2 to 3, or from 2 to 4. In some embodiments, n
is 1 or 3. In some embodiments, n is 3. C.sub.nF.sub.2n may be
linear or branched. In some embodiments, C.sub.nF.sub.2n can be
written as (CF.sub.2).sub.n, which refers to a linear
perfluoroalkylene group. In some embodiments, C.sub.nF.sub.2n is
--CF.sub.2--CF.sub.2--CF.sub.2--. In some embodiments,
C.sub.nF.sub.2n is branched, for example,
--CF.sub.2--CF(CF.sub.3)--. In some embodiments,
(OC.sub.nF.sub.2n).sub.z is represented by
--O--(CF.sub.2).sub.1-4--[O(CF.sub.2).sub.1-4].sub.0-1. In some
embodiments, R.sub.f.sup.2 is a linear or branched perfluoroalkyl
group having from 1 to 8 (or 1 to 6) carbon atoms that is
optionally interrupted by up to 4, 3, or 2 --O-- groups. In some
embodiments, R.sub.f.sup.2 is a perfluoroalkyl group having from 1
to 4 carbon atoms optionally interrupted by one --O-- group.
Suitable monomers represented by formula
CF.sub.2.dbd.CFOR.sub.f.sup.2 and
CF.sub.2.dbd.CF(OC.sub.nF.sub.2n).sub.zOR.sub.f.sup.2 include
perfluoromethyl vinyl ether, perfluoroethyl vinyl ether,
perfluoropropyl vinyl ether, CF.sub.2.dbd.CFOCF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CF.sub.2CF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.2CF.sub.2OCF.sub.-
3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.2CF.sub.2CF.sub-
.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2(OCF.sub.2).sub.3OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2(OCF.sub.2).sub.4OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2OCF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.3
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.-
3, CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)--O--C.sub.3F.sub.7
(PPVE-2),
CF.sub.2.dbd.CF(OCF.sub.2CF(CF.sub.3)).sub.2--O--C.sub.3F.sub.7
(PPVE-3), and
CF.sub.2.dbd.CF(OCF.sub.2CF(CF.sub.3)).sub.3--O--C.sub.3F.sub.7
(PPVE-4). Many of these perfluoroalkoxyalkyl vinyl ethers can be
prepared according to the methods described in U.S. Pat. Nos.
6,255,536 (Worm et al.) and 6,294,627 (Worm et al.).
[0056] Suitable fluoro (alkene ether) monomers include those
described in U.S. Pat. No. 5,891,965 (Worm et al.) and U.S. Pat.
No. 6,255,535 (Schulz et al.). Such monomers include those in which
n is 0 and which are represented by formula
CF.sub.2.dbd.CF(CF.sub.2).sub.m--O--R.sub.f.sup.2, wherein m is 1,
and wherein R.sub.f.sup.2 is as defined above in any of its
embodiments. Suitable perfluoroalkoxyalkyl allyl ethers include
those represented by formula
CF.sub.2.dbd.CFCF.sub.2(OC.sub.nF.sub.2n).sub.zOR.sub.f.sup.2, in
which n, z, and Rf.sub.2 are as defined above in any of the
embodiments of perfluoroalkoxyalkyl vinyl ethers. Examples of
suitable perfluoroalkoxyalkyl allyl ethers include
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2CF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2CF.sub.2OCF.sub.2CF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2CF.sub.2CF.sub.2OCF.sub.2CF.sub.3-
, CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.2OCF.sub.-
3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.2CF.sub-
.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.2CF.sub.2-
CF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2(OCF.sub.2).sub.3OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2(OCF.sub.2).sub.4OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2OCF.sub.2OCF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2CF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.2OCF.sub.2CF.sub.-
2CF.sub.3,
CF.sub.2.dbd.CFCF.sub.2OCF.sub.2CF(CF.sub.3)--O--C.sub.3F.sub.7- ,
and
CF.sub.2.dbd.CFCF.sub.2(OCF.sub.2CF(CF.sub.3)).sub.2--O--C.sub.3F.su-
b.7. Many of these perfluoroalkoxyalkyl allyl ethers can be
prepared, for example, according to the methods described in U.S.
Pat. No. 4,349,650 (Krespan).
[0057] In some embodiments, the fluoropolymer useful in the
compositions and articles of the present disclosure is an amorphous
fluoropolymer. Amorphous fluoropolymers typically do not exhibit a
melting point and exhibit little or no crystallinity at room
temperature. Useful amorphous fluoropolymers can have glass
transition temperatures below room temperature or up to 280.degree.
C. Suitable amorphous fluoropolymers can have glass transition
temperatures in a range from -60.degree. C. up to 280.degree. C.,
-60.degree. C. up to 250.degree. C., from -60.degree. C. to
150.degree. C., from -40.degree. C. to 150.degree. C., from
-40.degree. C. to 100.degree. C., or from -40.degree. C. to
20.degree. C. Amorphous fluoropolymers include, for example,
copolymers of vinylidene fluoride and at least one terminally
ethylenically-unsaturated fluoromonomer containing at least one
fluorine atom substituent on each double-bonded carbon atom, each
carbon atom of said fluoromonomer being substituted only with
fluorine and optionally with chlorine, hydrogen, a lower
fluoroalkyl radical, or a lower fluoroalkoxy radical. Specific
examples of copolymers include copolymers having units from a
combination of monomers as follows: VDF-HFP, TFE-P, VDF-TFE-HFP,
VDF-TFE-PAVE, TFE-PAVE, E-TFE-PAVE and any of the aforementioned
copolymers further including units derived from a chlorine
containing monomer such as CTFE. Still further examples of suitable
amorphous copolymers include copolymers having a combination of
monomers as in CTFE-P.
[0058] Those skilled in the art are capable of selecting specific
interpolymerized units at appropriate amounts to form an amorphous
fluoropolymer. In some embodiments, the amorphous fluoropolymers
comprise from 20 to 85%, in some embodiments, 50 to 80% by moles of
repeating units derived from VDF and TFE, which may or may not be
copolymerized with one or more other fluorinated ethylenically
unsaturated monomer, such as HFP, and/or one or more
non-fluorinated C.sub.2-C.sub.8 olefins, such as ethylene and
propylene. When included, the units derived from the fluorinated
ethylenically unsaturated comonomer are generally present at
between 5 and 45 mole %, e.g., between 10 and 40 mole %, based on
the total moles of comonomers in the fluoropolymer. When included,
the units derived from the non-fluorinated comonomers are generally
present at between 1 and 50 mole %, e.g., between 1 and 30 mole %,
based on the total moles of comonomers in the fluoropolymer.
[0059] Examples of amorphous fluoropolymers useful in the
compositions and articles of the present disclosure include a
TFE/propylene copolymer, a TFE/propylene/VDF copolymer, a VDF/HFP
copolymer, a TFE/VDF/HFP copolymer, a TFE/PMVE copolymer, a
TFE/CF.sub.2.dbd.CFOC.sub.3F.sub.7 copolymer, a
TFE/CF.sub.2.dbd.CFOCF.sub.3/CF.sub.2.dbd.CFOC.sub.3F.sub.7
copolymer, a TFE/ethyl vinyl ether (EVE) copolymer, a TFE/butyl
vinyl ether (BVE) copolymer, a TFE/EVE/BVE copolymer, a
VDF/CF.sub.2.dbd.CFOC.sub.3F.sub.7 copolymer, an ethylene/HFP
copolymer, a TFE/HFP copolymer, a CTFE/VDF copolymer, a TFE/VDF
copolymer, a TFE/VDF/PMVE/ethylene copolymer, and a
TFENDF/CF.sub.2.dbd.CFO(CF.sub.2).sub.3OCF.sub.3 copolymer.
[0060] Amorphous fluoropolymers useful for practicing the present
disclosure may have a Mooney viscosity in a range from 0.1 to 100
(ML 1+10) at 100.degree. C. according to ASTM D1646-06 TYPE A. In
some embodiments, amorphous fluoropolymers useful for practicing
the present disclosure have a Mooney viscosity in a range from 0.1
to 25, 0.1 to 20, 0.1 to 10, or 0.1 to 5 (ML 1+10) at 100.degree.
C. according to ASTM D1646-06 TYPE A.
[0061] In some embodiments, the fluoropolymer useful in the
compositions and articles of the present disclosure is an
amorphous, curable fluoropolymer. Amorphous fluoropolymers can
include a cure site to render them curable. In some embodiments,
the fluoropolymer useful in the compositions and articles of the
present disclosure comprises a chloro, bromo-, or iodo-cure site.
In some embodiments, the fluoropolymer comprises a bromo- or
iodo-cure site. In some of these embodiments, the fluoropolymer
comprises an iodo-cure site. The cure site can be an iodo-, bromo-,
or chloro-group chemically bonded at the end of a fluoropolymer
chain. The weight percent of elemental iodine, bromine, or chlorine
in the amorphous fluoropolymer may range from about 0.2 wt. % to
about 2 wt. %, and, in some embodiments, from about 0.3 wt. % to
about 1 wt. %, based on the total weight of the fluoropolymer. To
incorporate a cure site end group into the amorphous fluoropolymer,
any one of an iodo-chain transfer agent, a bromo-chain transfer
agent or a chloro-chain transfer agent can be used in the
polymerization process. For example, suitable iodo-chain transfer
agents include perfluoroalkyl or chloroperfluoroalkyl groups having
3 to 12 carbon atoms and one or two iodo-groups. Examples of
iodo-perfluoro-compounds include 1,3-diiodoperfluoropropane,
1,4-diiodoperfluorobutane, 1, 6-diiodoperfluorohexane,
1,8-diiodoperfluorooctane, 1,10-diiodoperfluorodecane,
1,12-diiodoperfluorododecane,
2-iodo-1,2-dichloro-1,1,2-trifluoroethane,
4-iodo-1,2,4-trichloroperfluorobutane and mixtures thereof.
Suitable bromo-chain transfer agents include perfluoroalkyl or
chloroperfluoroalkyl groups having 3 to 12 carbon atoms and one or
two iodo-groups.
[0062] Chloro-, bromo-, and iodo-cure site monomers may also be
incorporated into the amorphous fluoropolymer by including cure
site monomers in the polymerization reaction. Examples of cure site
monomers include those of the formula CX.sub.2.dbd.CX(Z), wherein
each X is independently H or F, and Z is I, Br, or R.sub.f--Z,
wherein Z is I or Br and R.sub.f is a perfluorinated or partially
fluorinated alkylene group optionally containing O atoms. In
addition, non-fluorinated bromo-or iodo-substituted olefins, e.g.,
vinyl iodide and allyl iodide, can be used. In some embodiments,
the cure site monomers is CH.sub.2.dbd.CHI, CF.sub.2.dbd.CHI,
CF.sub.2.dbd.CFI, CH.sub.2.dbd.CHCH.sub.2I,
CF.sub.2.dbd.CFCF.sub.2I, CH.sub.2.dbd.CHCF.sub.2CF.sub.2I,
CF.sub.2.dbd.CFCH.sub.2CH.sub.2I, CF.sub.2.dbd.CFCF.sub.2CF.sub.2I,
CH.sub.2.dbd.CH(CF.sub.2).sub.6CH.sub.2CH.sub.2I,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2I,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CF.sub.2I,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2CH.sub.2I,
CF.sub.2.dbd.CFCF.sub.2OCH.sub.2CH.sub.2I,
CF.sub.2.dbd.CFO(CF.sub.2).sub.3OCF.sub.2CF.sub.2I,
CH.sub.2.dbd.CHBr, CF.sub.2.dbd.CHBr, CF.sub.2.dbd.CFBr,
CH.sub.2.dbd.CHCH.sub.2Br, CF.sub.2.dbd.CFCF.sub.2Br,
CH.sub.2.dbd.CHCF.sub.2CF.sub.2Br,
CF.sub.2.dbd.CFOCF.sub.2CF.sub.2Br, CF.sub.2.dbd.CFCl,
CF.sub.2.dbd.CFCF.sub.2Cl, or a mixture thereof.
[0063] Other cure-site monomers useful in the polymerization
reaction to make a fluoropolymer include cyano-group containing
monomers. Examples of cyano-group containing monomers include
CF.sub.2.dbd.CF--CF.sub.2--O--Rf--CN;
CF.sub.2.dbd.CFO(CF.sub.2).sub.rCN;
CF.sub.2.dbd.CFO[CF.sub.2CF(CF.sub.3)O].sub.p(CF.sub.2).sub.vOCF(CF.sub.3-
)CN; and
CF.sub.2.dbd.CF[OCF.sub.2CF(CF.sub.3)].sub.kO(CF.sub.2).sub.uCN,
wherein r represents an integer from 2 to 12; p represents an
integer from 0 to 4; k represents 1 or 2; v represents an integer
from 0 to 6; u represents an integer from 1 to 6, Rf is a
perfluoroalkylene or a bivalent perfluoroether group. Specific
examples of cyano-group containing fluorinated monomers include
perfluoro (8-cyano-5-methyl-3,6-dioxa-1-octene),
CF.sub.2.dbd.CFO(CF.sub.2).sub.5CN, and
CF.sub.2.dbd.CFO(CF.sub.2).sub.3OCF(CF.sub.3)CN,
CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)OCF.sub.2CF.sub.2CN,
CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)OCF.sub.2CF(CF.sub.3)CN, and
CF.sub.2.dbd.CFOCF.sub.2CF(CF.sub.3)OCF.sub.2CF.sub.2CN.
[0064] The chain transfer agents having the cure site and/or the
cure site monomers can be fed into the reactor by batch charge or
continuously feeding. Because feed amount of chain transfer agent
and/or cure site monomer is relatively small compared to the
monomer feeds, continuous feeding of small amounts of chain
transfer agent and/or cure site monomer into the reactor is
difficult to control. Continuous feeding can be achieved by a blend
of the iodo-chain transfer agent in one or more monomers. Examples
of monomers useful for such a blend include hexafluoropropylene
(HFP) and perfluoromethyl vinyl ether (PMVE).
[0065] In some embodiments, the fluoropolymer useful in the
compositions and articles of the present disclosure is a
thermoplastic fluoropolymer. Useful thermoplastic fluoropolymers
are typically semi-crystalline and melt processable with melt flow
indexes in a range from 0.01 grams per ten minutes to 10,000 grams
per ten minutes (20 kg/372.degree. C.). Suitable semi-crystalline
fluoropolymers can have melting points in a range from 50.degree.
C. up to 325.degree. C., from 100.degree. C. to 325.degree. C.,
from 150.degree. C. to 325.degree. C., from 100.degree. C. to
300.degree. C., or from 80.degree. C. to 290.degree. C. A
semi-crystalline fluoropolymer, when evaluated by differential
scanning calorimetry (DSC), typically has at least one melting
point temperature (T.sub.m) of at least 50.degree. C., at least
60.degree. C., or at least 70.degree. C. and a measurable enthalpy,
for example, greater than 0 J/g, or even greater than 0.01 J/g. The
enthalpy is determined by the area under the curve of the melt
transition as measured by DSC using the method described in U.S.
Pat. Appl. Pub. No. 2018/0208743 (Fukushi et al.) and expressed as
Joules/gram (J/g). Any of the monomers described above can be
useful for making fluoropolymers can be useful for making
thermoplastic fluoropolymers, and a person skilled in the art is
capable of selecting specific interpolymerized units at appropriate
amounts to form a semi-crystalline fluoropolymer.
[0066] In some embodiments, the semi-crystalline fluoropolymer
useful for practicing the present disclosure is a random
fluorinated copolymer having units derived from at least the
following monomers: tetrafluoroethylene (TFE), hexafluoropropylene
(HFP), and vinylidene fluoride (VDF). In some embodiments, the
fluoropolymer is derived at least 20, 25 or even 30 wt. % and at
most 40, 50, 55, or even 60 wt. % TFE; at least 10, 15, or even 20
wt. % and at most 25 or even 30 wt. % HFP; and at least 15, 20, or
even 30 wt. % and at most 50, 55, or even 60 wt. % VDF. In some
embodiments, the semi-crystalline fluoropolymer has a Melt Flow
Index (MFI) greater than 5, 5.5, 6, or even 7 g/10 min at
265.degree. C. and 5 kg. MFI or Melt Flow Rate (MFR) can be used as
a measure of the ease of the melt of a thermoplastic fluoropolymer
to flow. As MFI is higher, flow is better. MFI is also an indirect
measurement of molecular weight. As MFI is higher, the molecular
weight is lower.
[0067] Further examples of semi-crystalline fluoropolymers include
copolymers having units from a combination of the following
monomers: VDF-CTFE, CTFE-TFE-P, VDF-CTFE-HFP, CTFE-TFE-PAVE, and
CTFE-E-TFE-PAVE.
[0068] In some embodiments, the semi-crystalline fluoropolymer
useful in the compositions and articles of the present disclosure
is a block copolymer having at least one semi-crystalline block. In
some embodiments, the block copolymer includes at least A and B
blocks in which the A block is a copolymer having units derived
from at least the following monomers: tetrafluoroethylene (TFE),
hexafluoropropylene (HFP), and vinylidene fluoride (VDF). In some
embodiments, the A block comprises 30 wt. % to 85 wt. % TFE; 5 wt.
% to 40 wt. % HFP; and 5 wt. % to 55 wt. % VDF; 30 wt. % to 75 wt.
% TFE; 5 wt. % to 35 wt. % HFP; and 5 wt. % to 50 wt. % VDF; or
even 40 wt. % to 70 wt. % TFE; 10 wt. % to 30 wt. % HFP; and 10 wt.
% to 45 wt. % VDF. The B block is a copolymer derived from at least
the following monomers: hexafluoropropylene (HFP), and vinylidene
fluoride (VDF). In some embodiments, the B block comprises 25 wt. %
to 65 wt. % VDF and 15 wt. % to 60 wt. % HFP; or even 35 wt. % to
60 wt. % VDF and 25 wt. % to 50 wt. % HFP. Further details
regarding such block copolymers and methods of making them can be
found in U.S. Pat. Appl. Publ. No. 2018/0194888 (Mitchell et
al.).
[0069] Other fluorinated block copolymers having at least one
semi-crystalline segment may also be useful in the compositions and
articles of the present disclosure. In some embodiments, the A
block is a copolymer having units derived from TFE and a
perfluoroolefin, for example, having 2 to 8 carbon atoms (e.g.,
hexafluoropropylene (HFP)). Generally, these perfluoroolefins are
used in amounts of at least 2 wt. %, 3, wt. % or 4 wt. % and at
most 5 wt. %, 10 wt. %, 15 wt. %, or 20 wt. %. Other comonomers may
be added in small amounts (e.g., less than 0.5 wt. %, 1 wt. %, 2
wt. %, 3 wt. %, or 5 wt. %). Such comonomers can include
fluorinated vinyl and allyl ethers as described above. In some
embodiments, the A block is a copolymer having units derived from
TFE or CTFE (e.g., at least 40 wt. % or 45 wt. %; and at most 50
wt. %, 55 wt. %, or 60 wt. %) and a non-fluorinated olefin (e.g.,
at least 40 wt. % or 45 wt . %; and at most 50 wt. %, 55 wt. %, or
60 wt. %). Such non-fluorinated olefins comprise 2 to 8 carbon
atoms (e.g., ethylene, propylene, and isobutylene). Other
comonomers may be added in small amounts (e.g., at least 0.1 wt. %,
0.5 wt. %, or 1 wt. % and at most 3 wt. %, 5 wt. %, 7 wt. %, or 10
wt. %). Such comonomers can include fluorinated olefins (e.g., VDF
or HFP) and fluorinated vinyl and allyl ethers as described above.
In some embodiments, the A block is a copolymer having units
derived from VDF; derived from only VDF or VDF and small amounts
(e.g., at least 0.1 wt. %, 0.3 wt. %, or 0.5 wt. % and at most 1
wt. %, 2 wt. %, 5 wt. %, or 10 wt. %) of other fluorinated
comonomers such as fluorinated olefins such as HFP, TFE, and
trifluoroethylene.
[0070] The thermoplastic fluoropolymer useful for the compositions
and articles of the present disclosure, including any of the
embodiments of the semi-crystalline fluoropolymers described above,
can include at least one of iodo-, bromo-, chloro-, or cyano-cure
sites. The cure sites can be incorporated into the fluoropolymer
using the cure site monomers and/or chain transfer agents described
above in any of their embodiments. In some embodiments,
thermoplastic fluoropolymer includes at least 0.05 wt. %, at least
0.1 wt. %, or at least 0.5 wt. % and at most 0.8 wt. % or at most 1
wt. % elemental chlorine, bromine, or iodine based on the weight of
the fluoropolymer. Fluoropolymers including CTFE units would
include a higher wt. % of elemental chlorine.
[0071] Curable block copolymers including cyano-cure sites or
incorporated bisolefin monomers as described in Int. Pat. Appl.
Pub. Nos. WO2018/136324 (Mitchell et al.) and WO 2018/136331
(Mitchell et al.) may also be useful semi-crystalline
fluoropolymers for the compositions and articles of the present
disclosure.
[0072] A fluoropolymer is typically prepared by a sequence of
steps, which can include polymerization, coagulation, washing, and
drying. In some embodiments, an aqueous emulsion polymerization can
be carried out continuously under steady-state conditions. In this
embodiment, for example, an aqueous emulsion of monomers (e.g.,
including any of those described above), water, emulsifiers,
buffers and catalysts are fed continuously to a stirred reactor
under optimum pressure and temperature conditions while the
resulting emulsion or suspension is continuously removed. In some
embodiments, batch or semibatch polymerization is conducted by
feeding the aforementioned ingredients into a stirred reactor and
allowing them to react at a set temperature for a specified length
of time or by charging ingredients into the reactor and feeding the
monomers into the reactor to maintain a constant pressure until a
desired amount of polymer is formed. After polymerization,
unreacted monomers are removed from the reactor effluent latex by
vaporization at reduced pressure. The fluoropolymer can be
recovered from the latex by coagulation.
[0073] The polymerization is generally conducted in the presence of
a free radical initiator system, such as ammonium persulfate. The
polymerization reaction may further include other components such
as chain transfer agents and complexing agents. The polymerization
is generally carried out at a temperature in a range from
10.degree. C. and 100.degree. C., or in a range from 30.degree. C.
and 80.degree. C. The polymerization pressure is usually in the
range of 0.3 MPa to 30 MPa, and in some embodiments in the range of
2 MPa and 20 MPa.
[0074] Adjusting, for example, the concentration and activity of
the initiator, the concentration of each of the reactive monomers,
the temperature, the concentration of the chain transfer agent, and
the solvent using techniques known in the art can control the
molecular weight of the fluoropolymer. In some embodiments,
amorphous fluoropolymers useful for practicing the present
disclosure have weight average molecular weights in a range from
10,000 grams per mole to 200,000 grams per mole. In some
embodiments, the weight average molecular weight is at least
15,000, 20,000, 25,000, 30,000, 40,000, or 50,000 grams per mole up
to 100,000, 150,000, 160,000, 170,000, 180,000, or up to 190,000
grams per mole. Amorphous fluoropolymers disclosed herein typically
have a distribution of molecular weights and compositions. Weight
average molecular weights can be measured, for example, by gel
permeation chromatography (i.e., size exclusion chromatography)
using techniques known to one of skill in the art.
[0075] In some embodiments, the fluoropolymers useful in the
composition and article of the present disclosure are curable by a
peroxide curing reaction. This means the fluoropolymers are curable
by one or more peroxide curing agents or the radicals generated by
the peroxide curing agents. Peroxide curatives include organic or
inorganic peroxides. Organic peroxides, particularly those that do
not decompose during dynamic mixing temperatures, can be useful.
The composition of the present disclosure and/or first composition
and/or second composition in the article of the present disclosure
can include a peroxide. In some embodiments, the peroxide is an
acyl peroxide. Acyl peroxides tend to decompose at lower
temperatures than alkyl peroxides and allow for lower temperature
curing. In some of these embodiments, the peroxide is
di(4-t-butylcyclohexyl)peroxydicarbonate,
di(2-phenoxyethyl)peroxydicarbonate, di(2,4-dichlorobenzoyl)
peroxide, dilauroyl peroxide, decanoyl peroxide,
1,1,3,3-tetramethylethylbutylperoxy-2-ethylhexanoate,
2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, disuccinic acid
peroxide, t-hexyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl)
peroxide, t-butyl peroxy-2-ethylhexanoate, benzoyl peroxide,
t-butylperoxy 2-ethylhexyl carbonate, or t-butylperoxy isopropyl
carbonate. In some of these embodiments, the peroxide is benzoyl
peroxide or a substituted benzoyl peroxide (e.g.,
di(4-methylbenzoyl) peroxide or di(2,4-dichlorobenzoyl) peroxide).
In some embodiments, the composition or article of the present
disclosure includes at least one of benzoyl peroxide, dicumyl
peroxide, di-tert-butyl peroxide,
2,5-di-methyl-2,5-di-tert-butylperoxyhexane, 2,4-dichlorobenzoyl
peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylchlorohexane,
tert-butyl peroxy isopropylcarbonate (TBIC), tert-butyl peroxy
2-ethylhexyl carbonate (TBEC), tert-amyl peroxy 2-ethylhexyl
carbonate, tert-hexylperoxy isopropyl carbonate, carbonoperoxoic
acid, O,O'-1,3-propanediyl OO,OO'-bis(1,1-dimethylethyl) ester,
tert-butylperoxy benzoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl
peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, laurel
peroxide, or cyclohexanone peroxide. The peroxide is present in the
composition or first composition in an amount effective to cure the
composition. In some embodiments, the peroxide is present in the
composition in a range from 0.5% by weight to 10% by weight based
on the weight of the fluoropolymer in the composition. In some
embodiments, the peroxide is present in the composition in a range
from 1% by weight to 5% by weight based on the weight of the
fluoropolymer in the composition.
[0076] In some embodiments, compositions and articles of the
present disclosure include a crosslinker, which may be useful, for
example, for providing enhanced mechanical strength in the final
cured articles. Examples of useful crosslinkers include
tri(methyl)allyl isocyanurate (TMAIC), triallyl isocyanurate
(TAIC), tri(methyl)allyl cyanurate, poly-triallyl isocyanurate
(poly-TAIC), xylylene-bis(diallyl isocyanurate) (XBD),
N,N'-m-phenylene bismaleimide, diallyl phthalate,
tris(diallylamine)-s-triazine, triallyl phosphite, diallyl ether of
glycerin, triallylphosphate, diallyl adipate, diallylmelamine,
1,2-polybutadiene, ethyleneglycol diacrylate, diethyleneglycol
diacrylate, and CH.sub.2.dbd.CH--R.sub.f1--CH.dbd.CH.sub.2, wherein
R.sub.f1 is a perfluoroalkylene having from 1 to 8 carbon atoms.
The crosslinker is typically present in an amount of 1% by weight
to 10% by weight based on the weight of the fluoropolymer in the
composition or first composition. In some embodiments, the
crosslinker is present in a range from 2% by weight to 5% by weight
based on the weight of the fluoropolymer in the composition or
first composition.
[0077] Compositions according to the present disclosure and/or
useful in the articles of the present disclosure can be prepared by
compounding fluoropolymer, branched silsesquioxane polymer,
peroxide, and optionally the crosslinker described above.
Compounding can be carried out, for example, on a roll mill (e.g.,
two-roll mill), internal mixer (e.g., Banbury mixers), or other
rubber-mixing device. Thorough mixing is typically desirable to
distribute the components and additives uniformly throughout the
composition so that it can cure effectively. It is typically
desirable that the temperature of the composition during mixing
should not rise high enough to initiate curing. For example, the
temperature of the composition may be kept at or below about
50.degree. C.
[0078] Additives such as carbon black, stabilizers, plasticizers,
lubricants, fillers, and processing aids typically utilized in
fluoropolymer compounding can be incorporated into the curing
compositions, provided they have adequate stability for the
intended service conditions. In particular, low temperature
performance can be enhanced by incorporation of
perfluoropolyethers. See, for example, U.S. Pat. No. 5,268,405 to
Ojakaar et al. Carbon black fillers can be employed in
fluoropolymers as a means to balance modulus, tensile strength,
elongation, hardness, abrasion resistance, conductivity, and
processability of the compositions. Suitable examples include MT
blacks (medium thermal black) and large particle size furnace
blacks. When used, 1 to 100 parts filler per hundred parts
fluoropolymer (phr) of large size particle black is generally
sufficient.
[0079] Fluoropolymer fillers may also be present in the curable
compositions. Generally, from 1 to 100 phr of fluoropolymer filler
can be useful. The fluoropolymer filler can be finely divided and
easily dispersed as a solid at the highest temperature used in
fabrication and curing of the composition disclosed herein. By
solid, it is meant that the filler material, if partially
crystalline, will have a crystalline melting temperature above the
processing temperature(s) of the curable composition(s). One way to
incorporate fluoropolymer filler is by blending latices. This
procedure, using various kinds of fluoropolymer filler, is
described in U.S. Pat. No. 6,720,360 (Grootaert et al.).
[0080] Conventional adjuvants may also be incorporated into the
composition and/or first composition disclosed herein to enhance
the properties of the composition. For example, acid acceptors may
be employed to facilitate the cure and thermal stability of the
composition. Suitable acid acceptors may include magnesium oxide,
lead oxide, calcium oxide, calcium hydroxide, dibasic lead
phosphite, zinc oxide, barium carbonate, strontium hydroxide,
calcium carbonate, hydrotalcite, alkali stearates, magnesium
oxalate, or combinations thereof. The acid acceptors can be used in
amounts ranging from about 1 to about 20 parts per 100 parts by
weight of the fluoropolymer.
[0081] The composition of the present disclosure can be used to
make cured fluoroelastomers in the form of a variety of articles,
including final articles, such as O-rings, and/or preforms from
which a final shape is made, (e.g. a tube from which a ring is
cut). To form an article, the composition can be extruded using a
screw type extruder or a piston extruder. The extruded or
pre-formed compositions can be cured in an oven at ambient
pressure.
[0082] Alternatively, the composition can be shaped into an article
using injection molding, transfer molding, or compression molding.
Injection molding of the composition, for example, can be carried
out by masticating the curable composition in an extruder screw,
collecting it in a heated chamber from which it is injected into a
hollow mold cavity by means of a hydraulic piston. After curing,
the article can then be demolded. Advantages of injection molding
process include short molding cycles, little or no preform
preparation, little or no flash to remove, and low scrap rate. The
branched silsesquioxane polymer in the compositions and crosslinked
articles of the present disclosure may be useful, for example, for
preventing or minimizing fouling of the mold.
[0083] The composition of the present disclosure can also be used
to prepare cure-in-place gaskets (CIPG) or form-in-place gaskets
(FIPG). A bead or thread of the composition can be deposited from a
nozzle onto a substrates surface. After forming to a desired gasket
pattern, the composition may be cured in place with a heat or in an
oven at ambient pressure.
[0084] The composition of the present disclosure can also be useful
as a fluoroelastomer caulk, which can be useful, for example, to
fill voids in, coat, adhere to, seal, and protect various
substrates from chemical permeation, corrosion, and abrasion, for
example. Fluoroelastomer caulk can be useful as a joint sealant for
steel or concrete containers, seals for flue duct expansion joints,
door gaskets sealants for industrial ovens, fuel cell sealants or
gaskets, and adhesives for bonding fluoroelastomer gaskets (e.g.,
to metal). In some embodiments, the composition can be dispensed by
hand and cured with heat at ambient pressure.
[0085] For any of the above embodiments of the composition and/or
first composition, the cure temperature can be selected based on
the decomposition temperature of the peroxide. For example, a
temperature can be selected that is above (in some embodiments, at
least 10.degree. C., 20.degree. C., 30.degree. C., 40.degree. C.,
or at least 50.degree. C. above) the ten-hour half-life temperature
of the peroxide. In some embodiments, the cure temperature is above
100.degree. C. In some embodiments, the cure temperature is in a
range from 120.degree. C. to 180.degree. C. The cure time can be at
least 5, 10, 15, 20, or 30 minutes up to 24 hours, depending on the
composition of the amorphous fluoropolymer and the cross-sectional
thickness of the cured article.
[0086] A cured fluoroelastomer can be post-cured, for example, in
an oven at a temperature of about 120.degree. C. to 300.degree. C.,
in some embodiments, at a temperature of about 150.degree. C. to
250.degree. C., for a period of about 30 minutes to about 24 hours
or more, depending on the chemical composition of the
fluoroelastomer and the cross-sectional thickness of the
sample.
[0087] As described above, the beneficial properties of
fluoropolymers include high temperature resistance, chemical
resistance (e.g., resistance to solvents, fuels, and corrosive
chemicals), and non-flammability. At least because of these
beneficial properties, fluoropolymers find wide application
particularly where materials are exposed to high temperatures or
aggressive chemicals. For example, because of their excellent
resistance to fuels and their good barrier properties,
fluoropolymers are commonly used in fuel management systems
including fuel tanks, and fuel lines (e.g., fuel filler lines and
fuel supply lines).
[0088] However, fluoropolymers are generally more expensive than
polymers that do not contain fluorine. To reduce the overall cost
of an article, a fluoropolymer is sometimes used in combination
with other materials. For example, articles containing
fluoropolymers can be prepared as multi-layer articles using a
relatively thin layer of a fluoropolymer, typically a
fluoroelastomer, at the interface where chemical resistance is
required, such as an inner or an outer layer. The other layers of
such multi-layer articles contain non-fluorine containing
elastomers, such as EPDM rubber or silicone-containing polymers.
One requirement of those layered articles is a firm and reliable
bond between the fluoropolymer layer and its adjacent layer(s).
However, satisfactory bonding of a fluoropolymer to other polymers,
particularly silicones, is often difficult, particularly after
prolonged exposure to elevated temperatures.
[0089] The present disclosure provides an article comprising a
first composition comprising a fluoropolymer in contact with a
second composition comprising a silicone, wherein at least one of
the first composition or second composition comprises the branched
silsesquioxane polymer described above in any of its embodiments.
Silicone resins useful in the second composition are also called
polysiloxanes, which comprise repeating --Si--O--Si-- units.
Typically, the polysiloxanes comprise polydimethylsiloxane. In some
embodiments, the silicone resins are curable. The
silicone-containing polymers may become elastic upon curing or
their elastic properties may increase upon curing; accordingly,
silicones useful for the articles of the present disclosure include
those that are elastomeric. The silicone-containing polymers may be
curable by a peroxide curing reaction. Such peroxide curable
silicone-containing polymers typically comprise methyl and/or vinyl
groups. The same peroxides and combinations of peroxides and
crosslinkers described above with respect to the peroxide-curable
fluoropolymers may be used. The cross-link density of the cured
silicone polymer may depend on both the vinyl or methyl level of
the silicone polymer and the amount of curing agent. Peroxides are
typically used in amount between 0.1 to 10 parts per hundred parts
of the curable silicone polymer. In some embodiments, the second
composition comprising a silicone includes from 0.5 to 3 parts per
hundred parts of a peroxide. The peroxide used in the second
composition of the article may be the same or different from the
one in the first composition. For example, different agents which
are activated at different temperatures can be used such that the
fluoropolymer in the first composition may cure before or after the
silicone polymer in the second composition. Peroxide curable
silicone polymers are commercially available, for example under the
trade designation Elastosil R 401/60 and Elastosil R 760/70 from
Wacker Chemie AG, Munich, Germany.
[0090] In some embodiments, the silicone in the second composition
is represented by formula:
(R')(R.sup.3).sub.2SiO[(R.sup.2SiO].sub.r--[(ZY)R.sup.2SiO].sub.s--Si(R.-
sup.3).sub.2(R').
In this formula, each R' is independently R.sup.3 or a terminal
unit represented by formula --Y--Z; R.sup.2, R.sup.3, Y, and Z are
as defined above in any of their embodiments; and r'+s' is in a
range from 10 to 500, 10 to 400, 10 to 300, 12 to 300, 13 to 300,
13 to 200, 10 to 100, 10 to 50, or 10 to 30. In some embodiments,
r' is 0, and s' is in a range from 20 to 200, 30 to 100, or 10 to
100. In some embodiments, s' is 0, and r' is in a range from 20 to
200, 30 to 100, or 10 to 100. In some embodiments when s' is 0, at
least one R' is represented by formula --Y--Z. In some embodiments,
at least 40 percent, and in some embodiments at least 50 percent,
of the R.sup.2 and R.sup.3 groups are phenyl, methyl, or
combinations thereof. For example, at least 60 percent, at least 70
percent, at least 80 percent, at least 90 percent, at least 95
percent, at least 98 percent, or at least 99 percent of the R.sup.2
and R.sup.3 groups can be phenyl, methyl, or combinations thereof.
In some embodiments, at least 40 percent, and in some embodiments
at least 50 percent, of the R.sup.2 and R.sup.3 groups are methyl.
For example, at least 60 percent, at least 70 percent, at least 80
percent, at least 90 percent, at least 95 percent, at least 98
percent, or at least 99 percent of the R.sup.2 and R.sup.3 groups
can be methyl. In some embodiments, each R.sup.2 and R.sup.3 is
methyl. Although the formula is shown as a block copolymer, it
should be understood that the divalent units can be randomly
positioned in the copolymer. Thus, polyorganosiloxanes useful for
practicing the present disclosure also include random
copolymers.
[0091] The silicone-containing polymers may alternatively or in
addition also be curable by use of metal containing compounds. This
means they can be cured by a so-called addition curing system. In
this system the polymers are cured by using a metal catalyst.
Suitable metal catalysts include platinum containing compounds,
especially platinum salts or platinum complexes having organic
ligands or residues. The corresponding curable silicones are
referred to as "platinum-curable". Silicone-containing polymers
that are curable by metal compounds typically contain reactive
groups such as vinyl groups. Examples of suitable platinum group
metal containing catalysts include platinic chloride, salts of
platinum, chloroplatinic acid, and various complexes. In some
embodiments, transition metal catalyst is chloroplatinic acid,
complexed with a siloxane such as tetramethylvinylcyclosiloxane
(i.e. 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclosiloxane) or
1,3-divinyl-1,1,3,3-tetramethyldisiloxane. In some embodiments, the
transition metal catalyst is a
platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex
(i.e., Karstedt's catalyst).
[0092] The silicone polymer composition may also contain silicones
comprising Si-H groups. Those silicones may act as crosslinkers,
for example, for vinyl-substituted silicones.
[0093] Metal-curable silicone polymers can be used as a one-part
silicone system or a two-part silicone system. One-part metal
(platinum) curable silicone polymers are commercially available,
for example, under the trade designation Elastosil R plus 4450/60
and Elastosil R plus 4110/70 from Wacker Chemie AG, Germany. In a
two-part silicone system, also referred to as liquid silicone
rubber (LSR), a vinyl-functional silicone polymer (typically
identified as part A) may be vulcanized in presence of a silicone
having Si--H groups (part B). Part A typically contains the
platinum catalyst. Two-part platinum curable silicone systems are
commercially available, for example under the trade designation
Elastosil R 533/60 A/B and Elastosil LR 7665 from Wacker Chemie, AG
and Silastic 9252/900P from Dow Corning. Examples of useful
platinum catalysts are known in the art. The platinum catalyst is
typically used in amounts between 2 and 200 ppm platinum.
[0094] In addition to the silicone resin, the second composition
may contain curing agents, catalysts and crosslinkers, including,
for example, the peroxides and crosslinkers described above. The
second composition may further include other fillers and additives
including those described above in connection with fluoropolymer
compositions.
[0095] In some embodiments of the article of the present
disclosure, at least one of the first composition comprising the
fluoropolymer or the second composition comprising the silicone
comprises the branched silsesquioxane polymer described above in
any of its embodiments. In some embodiments, the first composition
includes the branched silsesquioxane polymer. In some embodiments,
the second composition includes the branched silsesquioxane
polymer. In some embodiments, both the first and the second
composition include the branched silsesquioxane polymer. In some
embodiments, the same branched silsesquioxane polymer is used in
both the first and second compositions. In some embodiments,
branched silsesquioxane polymers used in the first and second
compositions are independently selected.
[0096] A wide range of amounts of the branched silsesquioxane
polymer described above may be useful in the first and/or second
composition. When added to the fluoropolymer composition, the
branched silsesquioxane polymer can be used in a range from 0.1%
and 10% by weight, in some embodiments from 0.5% and 5% by weight,
based on the weight of fluoropolymer. When added to the silicone
composition, the branched silsesquioxane polymer can be used in an
amount from 0.1% to 15% by weight, in some embodiments from 1% and
10% by weight, based on the weight of silicone in the composition.
When added to both the fluoropolymer composition and the silicone
composition, the branched silsesquioxane polymer can be used in an
amount of 0.1% to 5% by weight in the fluoropolymer composition
(based on the weight of the fluoropolymer in the composition) and
in an amount of 0.1% to 10% by weight in the silicone composition
(based on the weight of the silicone polymer in the
composition).
[0097] In some embodiments, the first composition is formed into a
sheet, a layer, a laminate, a tube, or other article, and the
second composition is formed into a sheet, a layer, a laminate, a
tube, or other article.
[0098] The compositions may then be laminated together using
effective heat and pressure for an effective time to create a
strong bond. As is known by one of ordinary skill, the effective
amount of heat, pressure, and time are interrelated, and may also
depend in the specific fluoropolymer and silicone compositions.
Effective and optimum bonding conditions may be determined by
routine experimentation.
[0099] For example, bonding may be achieved by contacting the first
and second compositions such that a common interface is formed. The
compositions are then subjected to conditions such that at least
the fluoropolymer cures. In some embodiments, the silicone polymer
may also cure. It may be sufficient to cure locally, i.e. to cure
only the parts of the compositions that form the common
interface.
[0100] In some embodiments, curing and bonding may be achieved by
heating the first composition while it is in contact with second
composition to a temperature of 120.degree. C. to 200.degree. C.
for 1 to 120 minutes (e.g., 140.degree. C. to 180.degree. C. for 3
to 60 minutes). In some embodiments, the heating may be carried out
while simultaneously applying pressure, e.g., at least 5 MPa, at
least 10 MPa, or even at least 25 MPa. Generally, pressures greater
than 200 MPa are not required. In some embodiments, the pressure is
no greater than 100 MPa, e.g. no greater than 50 MPa.
[0101] Alternatively, both compositions in the article may be in
molten form, for example, during co-extrusion or injection molding.
It is also possible to coat one of the compositions onto the other.
For example, one of the compositions may be a liquid or in the form
of a liquid coating composition. Such a composition may be applied
as a coating to the other composition, which may be provided in the
form of, e.g., a layer, a sheet, a film a laminate, a tube or other
article.
[0102] Alternative methods of forming articles of the present
disclosure include coextrusion, sequential extrusion, and injection
molding. It is also possible to prepare a multilayer article by a
repeated cycle of coating a liquid silicone polymer composition
onto a layer of a fluoropolymer composition. It is also possible to
form one or more individual layers by extrusion coating, e.g.,
using a crosshead die.
[0103] The heat and pressure of the method by which the layers are
brought together (e.g. extrusion or lamination) can be sufficient
to provide adequate adhesion between the compositions. It may,
however, be desirable to further treat the resulting article, for
example, with additional heat, pressure, or both, to enhance the
bond strength between the layers and to post cure the laminate. One
way of supplying additional heat when the article is prepared by
extrusion is by delaying the cooling of the article at the
conclusion of the extrusion process.
[0104] Alternatively, additional heat energy can be added to the
article by laminating or extruding the compositions at a
temperature higher than necessary for merely processing the
composition. As another alternative, the finished article can be
held at an elevated temperature for an extended period of time. For
example, the finished article can be placed in a separate apparatus
for elevating the temperature of the article such as an oven, an
autoclave or heated liquid bath. Combinations of these methods can
also be used.
[0105] An example of an article according to some embodiments of
the present disclosure, in the form of a simple two-layer laminate,
is shown in the FIG. 2. Article (100) comprises first layer (110),
bonded to second layer (120) at interface (130). First layer (110)
comprises the first composition, i.e., the fluoropolymer containing
composition. Second layer (120) comprises the second composition,
i.e., the silicone polymer containing composition. One or both the
first and second compositions comprise a branched silsesquioxane
polymer described above in any of its embodiments.
[0106] An example of an article according to some embodiments of
the present disclosure, in the form of a simple two-layer hose, is
shown in the FIG. 3. Article (200) comprises first layer (210),
bonded to second layer (220) at interface (230). First layer (210)
comprises the first composition, i.e., the fluoropolymer containing
composition. Second layer (220) comprises the second composition,
i.e., the silicone polymer containing composition. One or both the
first and second compositions comprise a branched silsesquioxane
polymer described above in any of its embodiments.
[0107] Any article in which a fluoropolymer containing layer is
bonded to the silicone polymer layer can be made. Such articles
include hoses, tubes, O-rings, seals, diaphragms, valves,
containers or simple laminates. The articles may be used, for
example, in motor vehicles, such as motor crafts, aircrafts and
watercrafts and include turbo charger hoses, fuel lines, and fuel
tanks. Articles may also be used in medical applications, for
examples as tubes, hoses or lining in a medical apparatus or
valves, O-rings and seals in a medical apparatus or device.
[0108] Hoses can be made in which a layer of fluoropolymer
(typically an elastomer), generally as an innermost layer, is
bonded to a silicone polymer (typically a silicone rubber), as the
outer layer or as a middle layer.
[0109] The Examples below demonstrate that a wide variety of
branched silsesquioxane polymer are useful for crosslinking a wide
variety of fluoropolymers. Typically, when the branched
silsesquioxane polymer is used to crosslink a fluoropolymer to make
a fluorolastomer, the tear resistance of the fluoroelastomer is
higher than when a comparative fluoroelastomer is made in the
absence of the branched silsesquioxane polymer. See, for example,
Examples 6 to 8 versus Comparative Example 2 in the Examples below.
A comparative fluoroelastomer has the same fluoropolymer, fillers,
peroxide, and crosslinkers as the fluoroelastomer of the present
disclosure except the comparative fluoroelastomer is not
crosslinked with the branched silsesquioxane polymer. Typically,
and unexpectedly, fluoroelastomers crosslinked with the branched
silsesquioxane polymer have much lower compression set than
fluoroelastomers crosslinked with polysiloxanes that include
aliphatic carbon-carbon double bonds. See, for example, Examples 1,
3, 9, and 11 versus Comparative Examples 3 to 5 in the Examples,
below.
Some Embodiments of the Disclosure
[0110] In a first embodiment, the present disclosure provides a
composition comprising:
[0111] a fluoropolymer; and
[0112] a branched silsesquioxane polymer comprising terminal
--Si(R.sup.3).sub.3 groups and units represented by formula:
##STR00010##
[0113] wherein
[0114] * represents a bond to another silicon atom in the branched
silsesquioxane polymer;
[0115] each R is independently an organic group comprising an
aliphatic carbon-carbon double bond; and
[0116] each R.sup.3 is independently a non-hydrolyzable group with
the proviso that one R.sup.3 may be hydrogen.
[0117] In a second embodiment, the present disclosure provides the
composition of the first embodiment, further comprising a
non-fluorinated, curable polymer.
[0118] In the third embodiment, the present disclosure provides the
composition of the second embodiment, wherein the non-fluorinated,
curable polymer is an ethylene-propylene-diene or a silicone.
[0119] In a fourth embodiment, the present disclosure provides an
article comprising a first composition comprising a fluoropolymer
in contact with a second composition comprising a silicone, wherein
at least one of the first composition or second composition
comprises a branched silsesquioxane polymer comprising terminal
--Si(R.sup.3).sub.3 groups and units represented by formula:
##STR00011##
[0120] wherein
[0121] * represents a bond to another silicon atom in the branched
silsesquioxane polymer;
[0122] each R is independently an organic group comprising an
aliphatic carbon-carbon double bond; and
[0123] each R.sup.3 is independently a non-hydrolyzable group with
the proviso that one R.sup.3 may be hydrogen.
[0124] In a fifth embodiment, the present disclosure provides the
composition or article of the third or fourth embodiment, wherein
the silicone is a curable polydimethysiloxane.
[0125] In a sixth embodiment, the present disclosure provides the
composition or article of any one of the first to fifth
embodiments, wherein the branched silsesquioxane polymer further
comprises units represented by formula:
##STR00012##
wherein.
[0126] * represents a bond to another silicon atom in the branched
silsesquioxane polymer; and
[0127] each R.sup.2 is independently hydrogen or a non-hydrolyzable
group that does not include an aliphatic carbon-carbon double
bond.
[0128] In a seventh embodiment, the present disclosure provides the
composition or article of the sixth embodiment, wherein each
R.sup.2 is independently hydrogen, alkyl, aryl, alkylene at least
one of interrupted or terminated by arylene or heterocyclylene,
wherein alkyl and alkylene at least one of interrupted or
terminated by arylene or heterocyclylene are unsubstituted or
substituted with halogen and optionally interrupted by at least one
catenated --O--, and wherein aryl, arylene, and heterocyclylene are
unsubstituted or substituted by at least one alkyl, alkoxy,
halogen, or combination thereof.
[0129] In an eighth embodiment, the present disclosure provides the
composition or article of the sixth or seventh embodiment, wherein
each R.sup.2 is independently unsubstituted alkyl or alkyl
substituted by fluoro.
[0130] In a ninth embodiment, the present disclosure provides the
composition or article of any one of the first to eighth
embodiments, wherein each R is independently represented by --Y--Z,
wherein Y is a bond, alkylene, arylene, or alkylene at least one of
interrupted or terminated by arylene, --O--, --NR'--, or a
combination thereof, and wherein Z is --CH.dbd.CH.sub.2,
--O--CH.dbd.CH.sub.2, --O--C(O)--CH.dbd.CH.sub.2,
--O--C(O)--C(CH.sub.3).dbd.CH.sub.2, --NR'--C(O)--CH.dbd.CH.sub.2,
--NR'--C(O)--C(CH.sub.3).dbd.CH.sub.2, wherein R' is hydrogen or
alkyl having up to four carbon atoms.
[0131] In a tenth embodiment, the present disclosure provides the
composition or article of the ninth embodiment, wherein Y is a bond
or --CH.sub.2--, and wherein Z is --CH.dbd.CH.sub.2.
[0132] In an eleventh embodiment, the present disclosure provides
the composition or article any one of the first to tenth
embodiments, wherein each R.sup.3 is independently alkyl, aryl, or
alkyl substituted by fluoro and optionally interrupted by at least
one catenated --O-- group.
[0133] In a twelfth embodiment, the present disclosure provides the
composition or article of the eleventh embodiment, wherein each
R.sup.3 is independently alkyl having up to four carbon atoms.
[0134] In a thirteenth embodiment, the present disclosure provides
the composition or article of any one of the first to twelfth
embodiments, wherein the branched silsesquioxane polymer is present
in the composition in a range from 1 percent to 10 percent by
weight, based on the total weight of the fluoropolymer or silicone
in the composition, the first composition, and/or the second
composition.
[0135] In a fourteenth embodiment, the present disclosure provides
the composition or article of any one of the first to thirteenth
embodiments, wherein the fluoropolymer is an amorphous, curable
fluoropolymer.
[0136] In a fifteenth embodiment, the present disclosure provides
the composition or article of any one of the first to thirteenth
embodiments, wherein the fluoropolymer is a semi-crystalline
fluoropolymer.
[0137] In a sixteenth embodiment, the present disclosure provides
the composition or article of any one of the first to fifteenth
embodiments, wherein the fluoropolymer comprises at least one of
chloro-, bromo-, iodo-, or cyano-cure sites.
[0138] In a seventeenth embodiment, the present disclosure provides
the composition or article of the sixteenth embodiment, wherein the
fluoropolymer comprises at least one of iodo- or bromo-cure
sites.
[0139] In an eighteenth embodiment, the present disclosure provides
the composition or article of any one of the first to the
seventeenth embodiments, wherein the composition, the first
composition, and/or the second composition further comprises a
peroxide initiator.
[0140] In a nineteenth embodiment, the present disclosure provides
the composition or article of the eighteenth embodiment, wherein
the peroxide initiator comprises at least one of benzoyl peroxide,
dicumyl peroxide, di-tert-butyl peroxide,
2,5-di-methyl-2,5-di-tert-butylperoxyhexane, 2,4-dichlorobenzoyl
peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylchlorohexane,
tert-butyl peroxy isopropylcarbonate (TBIC), tert-butyl peroxy
2-ethylhexyl carbonate (TBEC), tert-amyl peroxy 2-ethylhexyl
carbonate, tert-hexylperoxy isopropyl carbonate, carbonoperoxoic
acid, O,O'-1,3-propanediyl OO,OO'-bis(1,1-dimethylethyl) ester,
tert-butylperoxy benzoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl
peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, laurel
peroxide, or cyclohexanone peroxide.
[0141] In a twentieth embodiment, the present disclosure provides
the composition or article of the eighteenth or nineteenth
embodiment, wherein the peroxide is present in the composition,
first composition, and/or second composition in a range from 0.5
percent to 10 percent by weight of the fluoropolymer or silicone in
the composition.
[0142] In a twenty-first embodiment, the present disclosure
provides the composition or article of any one of the first to
twentieth embodiments, wherein the composition, the first
composition and/or the second composition further comprises a
crosslinker, wherein the crosslinker is tri(methyl)allyl
isocyanurate (TMAIC), triallyl isocyanurate (TAIC),
tri(methyl)allyl cyanurate, poly-triallyl isocyanurate (poly-TAIC),
xylylene-bis(diallyl isocyanurate) (XBD), N,N'-m-phenylene
bismaleimide, diallyl phthalate, tris(diallylamine)-s-triazine,
triallyl phosphite, diallyl ether of glycerin, triallylphosphate,
diallyl adipate, diallylmelamine, 1,2-polybutadiene, ethyleneglycol
diacrylate, diethyleneglycol diacrylate, or
CH.sub.2.dbd.CH--R.sub.f2--CH.dbd.CH.sub.2, wherein R.sub.f1 is a
perfluoroalkylene having from 1 to 8 carbon atoms.
[0143] In a twenty-second embodiment, the present disclosure
provides the composition or article of the twenty-first embodiment,
wherein the crosslinker is present in the composition, first
composition, and/or second composition in a range from 1 percent to
10 percent by weight, based on the total weight of the
fluoropolymer or silicone in the composition.
[0144] In a twenty-third embodiment, the present disclosure
provides an article comprising a fluoropolymer crosslinked with a
branched silsesquioxane polymer comprising terminal
--Si(R.sup.3).sub.3 groups and units represented by formula:
##STR00013##
wherein
[0145] * represents a bond to another silicon atom in the branched
silsesquioxane polymer;
[0146] each R* is independently an organic group comprising a
carbon-carbon bond between the branched silsesquioxane polymer and
the fluoropolymer or another R* group in the branched
silsesquioxane polymer; and
[0147] each R.sup.3 is independently a non-hydrolyzable group with
the proviso that one R.sup.3 may be hydrogen.
[0148] In a twenty-fourth embodiment, the present disclosure
provides an article comprising a fluoropolymer in contact with a
silicone, wherein at least one of the fluoropolymer or the silicone
is crosslinked with a branched silsesquioxane polymer comprising
terminal --Si(R.sup.3).sub.3 groups and units represented by
formula:
##STR00014##
[0149] wherein
[0150] * represents a bond to another silicon atom in the branched
silsesquioxane polymer;
[0151] each R* is independently an organic group comprising a
carbon-carbon bond between the branched silsesquioxane polymer and
the fluoropolymer, the silicone, or another R* group in the
branched silsesquioxane polymer; and
[0152] each R.sup.3 is independently a non-hydrolyzable group with
the proviso that one R.sup.3 may be hydrogen.
[0153] In a twenty-fifth embodiment, the present disclosure
provides the article of the twenty-third or twenty-fourth
embodiment, wherein the branched silsesquioxane polymer further
comprises units represented by formula
##STR00015##
wherein.
[0154] * represents a bond to another silicon atom in the branched
silsesquioxane polymer; and each R.sup.2 is independently hydrogen
or a non-hydrolyzable group that does not include an aliphatic
carbon-carbon double bond.
[0155] In a twenty-sixth embodiment, the present disclosure
provides the article of the twenty-fifth embodiment, wherein each
R.sup.2 is independently hydrogen, alkyl, aryl, alkylene at least
one of interrupted or terminated by arylene or heterocyclylene,
wherein alkyl and alkylene at least one of interrupted or
terminated by arylene or heterocyclylene are unsubstituted or
substituted with halogen and optionally interrupted by at least one
catenated --O--, and wherein aryl, arylene, and heterocyclylene are
unsubstituted or substituted by at least one alkyl, alkoxy,
halogen, or combination thereof.
[0156] In a twenty-seventh embodiment, the present disclosure
provides the article of the twenty-sixth embodiment, wherein each
R.sup.2 is independently unsubstituted alkyl or alkyl substituted
by fluoro.
[0157] In a twenty-eighth embodiment, the present disclosure
provides the article of any one of the twenty-third to
twenty-seventh embodiments, wherein R* optionally further comprises
alkylene, arylene, or alkylene at least one of interrupted or
terminated by arylene, --O--, --NR'--, --O--C(O)--, --NR'--C(O)--,
or a combination thereof, and wherein R' is hydrogen or alkyl
having up to four carbon atoms.
[0158] In a twenty-ninth embodiment, the present disclosure
provides the article of the twenty-eighth embodiment, wherein R* is
the carbon-carbon bond optionally bonded to --CH.sub.2--.
[0159] In a thirtieth embodiment, the present disclosure provides
the article of any one of the twenty-third to twenty-ninth
embodiments, wherein each R.sup.3 is independently alkyl, aryl, or
alkyl substituted by fluoro and optionally interrupted by at least
one catenated --O-- group.
[0160] In a thirty-first embodiment, the present disclosure
provides the article of the thirtieth embodiment, wherein each
R.sup.3 is independently alkyl having up to four carbon atoms.
[0161] In a thirty-second embodiment, the present disclosure
provides the article of any one of the twenty-third to thirty-first
embodiments, wherein the fluoropolymer is amorphous.
[0162] In a thirty-third embodiment, the present disclosure
provides the article of any one of the twenty-third to thirty-first
embodiments, wherein the fluoropolymer is semi-crystalline.
[0163] In a thirty-fourth embodiment, the present disclosure
provides the article of any one of the fourth to thirty-third
embodiments, wherein the article is a hose, an O-ring, a seal, a
diaphragm, a valve, or a container.
[0164] The following specific, but non-limiting, examples will
serve to illustrate the present disclosure.
EXAMPLES
[0165] The following abbreviations are used in this section:
g=grams, lb=pounds, f=feet, in=inches, wt %=percent by weight,
min=minutes, h=hours, dNm=decinewton meters, MW=molecular weight,
.degree. F.=degrees Fahrenheit, .degree. C.=degrees Celsius,
TFE=tetrafluoroethylene, PMVE=perfluoromethyl vinyl ether,
vinylidene fluoride=VDF, chlorotrifluoroethylene=CTFE, and
hexafluoropropylene=HFP.
TABLE-US-00001 TABLE 1 Materials Used in the Examples Abbreviation
Description and Source FPO3820 Peroxide curing fluoropolymer (70%
fluorine terpolymer, Mooney Viscosity ML1 + 10 @ 121.degree. C. of
24, with iodine end groups), 3M Company, St. Paul, Minn. FPO3620
Peroxide curing fluoropolymer (67.5% fluorine terpolymer, Mooney
Viscosity ML1 + 10 @ 121.degree. C. of 20, with iodine end groups),
3M Company FP3 A fluorine-containing copolymer of TFE and PMVE with
72.2 wt % fluorine content, 0.3 wt % iodine content and Mooney
Viscosity ML1 + 10 @ 121.degree. C. of 40, obtained under the trade
designation "3M DYNEON PFE 40Z" from 3M Company FP4 A
fluoroelastomer that is derived from about 26.5% of TFE, 36.5% of
HFP and 37% of VDF by weight with 0.18% of bromine and 0.15% of
iodine by weight, 69.8 wt % fluorine content, and Mooney Viscosity
ML1 + 10 @ 121.degree. C. of 36 FP5 A fluoroelastomer that is
derived from 56.3% of VDF, and 43.7% of CTFE by weight, 54.9%
fluorine content. FP6 A fluoroelastomer derived from TFE and
propylene obtained from AGC Chemicals, Exton, Pa. under the trade
designation "AFLAS 150P" FP7 A fluoroelastomer that is derived from
about 11% of TFE, 51% of VDF and 38% of PMVE by weight with 0.3% of
iodine, 64.2% fluorine content, and Mooney viscosity ML1 + 10 @
121.degree. C. of 50 FP8 A fluoroelastomer that is derived from
about 16% of TFE, 31% of VDF and 53% of
CF.sub.2.dbd.CFO(CF.sub.2).sub.3OCF.sub.3 by weight with 0.12% of
bromine, 67.1% fluorine content, and Mooney Viscosity ML1 + 10 @
121.degree. C. of 95 N990 Carbon black obtained under the trade
designation "N990" from Cancarb, Medicine Hat, AB, Calif. TAIC
Triallyl-isocyanurate obtained under the trade designation "TAIC"
from Nippon Kasei Chemical Co. Ltd., Tokyo, Japan DBPH-50
2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, 50% active, obtained
under the trade designation "VAROX DBPH-50" from Vanderbilt
Chemicals, LLC., Norwalk, Conn. BPO 98% Benzoyl Peroxide, available
from MilliporeSigma, St. Louis, Mo. VMQ Linear vinylmethylsiloxane
homopolymer, available under the trade designation VMS-T11 from
Gelest, Morrisville, Pa. Divinyl Vinyl terminated
polydimethylsiloxane, PDMS available under the trade designation
DMS-V41 from Gelest Tetra Vinyl 1,3,5,7 Tetravinyl, 1,3,5,7
tetramethyl- cyclic cyclotetrasiloxane, available under the trade
siloxane designation SIT7900.0 from Gelest SLM19045 Wacker Chemie
AG, Munich, Germany SLM19046 Wacker Chemie AG
Test Methods
[0166] Cure rheology: Cure rheology tests were carried out using
uncured, compounded samples using a rheometer (PPA 2000 by Alpha
technologies, Akron, Ohio), in accordance with ASTM D 5289-93A at
177.degree. C., no pre-heat, 12 minute elapsed time, and a 0.5
degree arc. For Examples 13 and 16, 12 minutes at 130.degree. C.
was used. Both the minimum torque (M.sub.L) and highest torque
attained during a specified period of time when no plateau or
maximum torque (M.sub.H) was obtained were measured. Also reported
were the time for the torque to reach a value equal to
M.sub.L+0.5(M.sub.H-M.sub.L), and the time for the torque to reach
M.sub.L+0.9(M.sub.H-M.sub.L), (t'90). Results are reported in
Tables 3, 9, and 11.
[0167] Physical Properties: Sheet samples were molded for 10 min on
a Wabash MPI Model 76-1818-2TMAC press set to 177.degree. C. and 75
tons (68 metric tons). Post-curing conditions are given in Tables
3, 5, 7, 9, and 11 below. Tensile, elongation, and modulus data
were gathered from press cured and post cured samples cut at room
temperature to Die D specifications in accordance with ASTM
412-06A.
[0168] Molded O-rings and Compression Set: O-rings (214, AMS AS568)
were molded for 10 min on a Wabash MPI Model 76-1818-2TMAC press
set to 177.degree. C. and 50 tons (45 metric tons). The press cured
O-rings were post cured at 250.degree. C. for 16 h. The post cured
O-rings were tested for compression set for 70 h at 200.degree. C.
in accordance with ASTM D 395-03 Method B and ASTM D1414-94 with a
25% deflection. Results are reported as percentages.
[0169] Trouser Tear: Trouser tear samples were evaluated in
accordance with ISO34-1: 2015 method A.
[0170] Bonding evaluations: 10 g of the fluoropolymers outlined
below were placed in contact with 10 g of the silicone into a 1 in.
by 3 in. (2.54 cm.times.7.62 cm) rectangular mold. There was a 0.5
in. by 1.0 in. (1.27 cm by 2.54 cm) release liner placed between
the layers at one end. The layers were then pressed together for 10
min on a Wabash MPI Model 76-1818-2TMAC press set to 325.degree. F.
(162.8.degree. C.) and 74 tons (67 metric tons). The samples were
then post cured for 3 h at 200.degree. C. The samples were then
evaluated for bonding by carrying out a 180 peel test at 12.0
in/min (30.5 cm/min) in a tensiometer from MTS Systems Corporation,
Eden Prairie, Minn., following ASTM D413-76, type A.
[0171] Viscosity: Viscosity of Preparatory Examples 1 and 2 were
measured on a Brookfield DV-II+Viscometer with the LV4 spindle.
Preparatory Examples
Preparatory Example 1 (PE-1), Vinyl SSQ
[0172] To 50 g vinyltrimethoxysilane (Oakwood Chemical, Estill,
S.C.) was added 32 g deionized water. This was mixed using a
mechanical stirrer before 0.5 g 5 wt% HCl solution was added, and
the solution was heated at 65.degree. C. for 6 h. To this was added
10 g Ethoxytrimethylsilane (Oakwood Chemical) and heated at
65.degree. C. for 2 h. This was followed by cooling the mixture to
ambient temperature and then quenching the reaction by adding ice
water. Two layers formed and the bottom layer was decanted using a
separatory funnel and then washed with 100 g cold water 3 times.
The vinyl SSQ obtained was dried in a vacuum at 30.degree. C. for 8
h to remove residual water. The viscosity of Preparative Example 1
was 2100 centipoise (cps).
Preparatory Example 2 (PE-2), Allyl SSQ
[0173] Preparatory Example 2 was prepared using the method
described for PE-1, with the exception that allyltrimethoxysilane
(Oakwood Chemical) was used in place of vinyltrimethoxysilane. The
viscosity of Preparative Example 1 was 890 centipoise (cps).
Preparatory Example 3 (PE-3), Vinyl-Octadecyl SSQ
[0174] Preparatory Example 3 was prepared using the method
described for PE-1, with the exception that a portion of the
vinyltrimethoxysilane was replaced with n-octadecyltrimethoxysilane
(Gelest) to give a final weight ratio of 77.8
(vinyltrimethoxysilane) to 22.2 (n-octadecyltrimethoxysilane).
Preparative Example 3 was a waxy solid.
Preparatory Example 4 (PE-4), Vinyl-Perfluorohexylethyl SSQ
[0175] Preparatory Example 4 was prepared using the method
described for PE-1, with the exception that a portion of vinyl
trimethoxysilane was replaced with
1H,1H,2H,2H-Perfluorooctyltrimethoxysilane (Oakwood Chemical) to
give a final weight ratio of 80 (vinyl trimethoxysilane) to 20
(1H,1H,2H,2H-Perfluorooctyltrimethoxysilane).
[0176] Fluoropolymers, carbon black, SSQ or silane, TAIC, and
peroxide, in amounts as indicated in Tables 2, 4, 8, and 10 were
mixed on a 6 in (15.24 cm) open roll mill. For Silicone 1 and
Silicone 2, the silicones indicated in Table 6 were used as
received. For Silicone 3, the indicated silicone was banded on a 6
in (15.24 cm) open roll mill and the amount of vinyl SSQ indicated
in Table 6 was added dropwise while cutting and folding silicone
until it was incorporated completely. Milling continued for an
additional 10 min and then the silicone was removed from the
mill.
TABLE-US-00002 TABLE 2 Formulations for Vinyl SSQ and Allyl SSQ
Material CE-1 EX-1 EX-2 EX-3 EX-4 EX-9 EX-10 EX-11 EX-12 FPO3820
100 100 100 100 100 100 100 100 100 N990 30 30 30 30 30 30 30 30 30
PE-1 -- -- -- 3 3 -- -- -- -- PE-2 -- 3 3 -- -- -- -- -- -- PE-3 --
-- -- -- -- 3 3 -- -- PE-4 -- -- -- -- -- -- -- 3 3 TAIC 3 -- 3 --
3 -- 3 -- 3 DBPH-50 2 2 2 2 2 2 2 2 2
TABLE-US-00003 TABLE 3 Physical Properties Data CE-1 EX-1 EX-2 EX-3
EX-4 EX-9 EX-10 EX-11 EX-12 Cure Rheology (177.degree. C., 12 min)
M.sub.L, Minimum 0.38 0.66 0.45 0.71 0.49 0.6 0.4 1.0 0.8 Torque,
dNm t'50, Time to 0.71 1.62 1.36 0.71 0.74 0.8 0.7 0.8 0.8 50% cure
- mm t'90, Time to 1.20 5.55 3.69 2.15 1.48 3.1 1.5 2.3 1.5 90%
cure - min M.sub.H, Maximum 29.75 19.28 41.29 22.93 44.07 20.6 46.7
26.7 43.1 Torque, dNm Tensile Properties, Post Cure at 232.degree.
C. (450.degree. F.), 4 h Tensile, MPa 22.6 17.6 20.6 16.3 22.8 12.7
18.4 15.3 22.1 Elongation at 200 310 214 332 237 389 212 307 224
break, % 50% Modulus, 2.4 2.3 3.3 2.4 3.7 2.3 3.8 2.4 3.5 MPa 100%
Modulus, 7.3 4.1 7.3 4.3 8.2 3.4 7.7 4.6 8.1 MPa Hardness, 73 76 78
74 79 78 82 76 79 Shore A Compression Set 70 h at 200.degree. C.,
25% deflection Post Cure 20 62 27 49 20 59 21 55 23
TABLE-US-00004 TABLE 4 Formulations for Vinyl SSQ loading study
Material CE-2 EX-5 EX-6 EX-7 EX-8 FPO3620 100 100 100 100 100 N990
30 30 30 30 30 PE-1 0.5 1 2 3 TAIC 0.5 0.5 0.5 0.5 0.5 DBPH-50 2 2
2 2 2
TABLE-US-00005 TABLE 5 Tensile Data for Vinyl SSQ loading study
CE-2 EX-5 EX-6 EX-7 EX-8 Tensile Properties, Post Cure at
200.degree. C. (392.sup.o F.), 4 h Tensile, MPa 15.8 NM 19.9 11.8
14.6 Elongation at 374 NM 339 254 335 break, % 50% Modulus, 1.3 NM
1.7 1.9 1.9 MPa 100% 2.0 NM 3.0 3.5 3.3 Modulus, MPa Hardness, NM
68 69 69 64 Shore A Trouser Tear kN/m 5.6 NM 6.6 6.5 8.5 NM = not
measured
TABLE-US-00006 TABLE 6 Silicone formulation Silicone 1 Silicone 2
Silicone 3 SLM19045 100 -- -- SLM19046 -- 100 100 PE-1 -- -- 3
TABLE-US-00007 TABLE 7 Bonding of Fluoropolymer and Silicone
Tensile Properties, Post Cure at 200.degree. C. (392.sup.o F.), 3 h
CE-2 EX-6 EX-7 EX-8 Bond Strength, Silicone 1 4.9 NM NM 15.3 lbf/in
(Nm) (0.55) (1.73) Failure Mode AF ST Silicone 2 4.2 8.3 13.7 19.1
(0.48) (0.93) (1.55) (2.16) AF AF ST ST Silicone 3 8.1 NM NM 8.9
(0.92) (1.0) ST ST AF = adhesive failure ST = silicone tear NM =
not measured
TABLE-US-00008 TABLE 8 Formulations for other silanes Material CE-3
CE-4 CE-5 FPO3820 100 100 100 N990 30 30 30 VMQ 3 -- -- Divinyl
PDMS -- 3 -- Tetra Vinyl cyclic siloxane -- -- 3 DBPH-50 2 2 2
TABLE-US-00009 TABLE 9 Physical Properties Data CE-3 CE-4 CE-5 Cure
Rheology (177.degree. C., 12 min) M.sub.L, Minimum 1.6 1.6 1.6
Torque, dNm t'50, Time to 2.0 1.1 1.9 50% cure - min t'90, Time to
5.3 3.4 5.2 90% cure - min M.sub.H, Maximum 15.8 4.8 15.2 Torque,
dNm Tensile Properties, Post Cure at 232.degree. C. (450.sup.o F.),
4 h Tensile, MPa 19.3 6.9 18.6 Elongation at 325 673 313 break, %
50% Modulus, 1.6 1.4 1.8 MPa 100% Modulus, 3.2 1.9 3.3 MPa
Hardness, Shore 69 70 71 A Compression Set 70 h at 200.degree. C.,
25% deflection Post Cure 84 89 84
TABLE-US-00010 TABLE 10 Formulations for Examples 13 to 19 Material
EX-13 EX-14 EX-15 EX-16 EX-17 EX-18 EX-19 FPO3620 100 -- -- -- --
-- -- FP3 -- 100 -- -- -- -- -- FP4 -- -- 100 -- -- -- -- FP5 -- --
-- 100 -- -- -- FP6 -- -- -- -- 100 -- -- FP7 -- -- -- -- -- 100 --
FP8 -- -- -- -- -- -- 100 N990 30 30 30 30 30 30 30 PE-1 3 3 3 3 3
3 3 BPO 4 -- -- 4 -- -- -- DBPH-50 -- 2 2 -- 2 2 2
TABLE-US-00011 TABLE 11 Physical Properties Data EX-13 EX-14 EX-15
EX-16 EX-17 EX-18 EX-19 Cure rheology (Cure A: 177.degree. C., B A
A B A A A 12 mins) or (Cure B: 130.degree. C., 12 mins) M.sub.L,
Minimum Torque, N m 1.5 0.9 1.1 8.0 2.0 1.5 3.1 M.sub.H, Maximum
Torque, N m 21.2 34.6 13.7 14.2 7.2 19.3 10.7 t'50, Time to 50%
cure - minutes 0.6 0.49 0.9 0.6 1.55 0.7 0.7 t'90, Time to 90% cure
- minutes 1.1 1.02 2.4 1.7 6.15 1.7 1.7 tan d M.sub.L 0.75 0.95
0.81 0.38 0.67 0.74 0.46 tan d M.sub.H 0.078 0.03 0.171 0.195 0.274
0.111 0.177 Post Cure @ 232.degree. C. (450.degree. F.), 4 hours
Tensile, MPa 9.8 15.9 10.0 11.8 7.7 15.0 7.3 Elongation at break, %
398 174 259 352 491 413 372 50% Modulus, MPa 1.6 3.1 1.5 1.8 1.9
1.6 1.3 100% Modulus, MPa 2.5 7.6 3.4 2.9 3.5 2.7 2.1 Hardness,
Shore A 63 68 63 69 68 67 60 Compression Set 70 hours @200.degree.
C., 25% deflection post cure 52 34 NM 72 82 48 50
[0177] Various modifications and alterations of this disclosure may
be made by those skilled the art without departing from the scope
and spirit of this disclosure, and it should be understood that
this invention is not to be unduly limited to the illustrative
embodiments set forth herein.
* * * * *